From 32214e2e6ceadeda927cd1753616830fa9d40946 Mon Sep 17 00:00:00 2001
From: Chrissy
@@ -81,7 +81,7 @@
The formula
diff --git a/source/previews/PA-changing-composite-D.xml b/source/previews/PA-changing-composite-D.xml
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diff --git a/source/previews/PA-changing-functions-crickets-D.xml b/source/previews/PA-changing-functions-crickets-D.xml
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diff --git a/source/previews/PA-changing-inverse-F-C-D.xml b/source/previews/PA-changing-inverse-F-C-D.xml
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diff --git a/source/previews/PA-changing-linear-3-ex-D.xml b/source/previews/PA-changing-linear-3-ex-D.xml
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diff --git a/source/previews/PA-changing-tandem-aquarium-D.xml b/source/previews/PA-changing-tandem-aquarium-D.xml
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diff --git a/source/previews/PA-changing-transformations-quadratic-D.xml b/source/previews/PA-changing-transformations-quadratic-D.xml
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Explore by moving the slider for
diff --git a/source/previews/PA-circular-sinusoidal-D.xml b/source/previews/PA-circular-sinusoidal-D.xml
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diff --git a/source/previews/PA-circular-traversing-D.xml b/source/previews/PA-circular-traversing-D.xml
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- In the context of the ferris wheel pictured in Figure 2.1.1 in the text, assume that the height,
+
Further, assume that the circumference of the ferris wheel is
- In the following figure there are 24 equally spaced points on the unit circle. Since the circumference of the unit circle is
@@ -22,7 +22,7 @@
- By experimenting with the value of
- Similarly, experiment to find a value of
diff --git a/source/previews/PA-exp-log-D.xml b/source/previews/PA-exp-log-D.xml
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Suppose that
diff --git a/source/previews/PA-exp-modeling-D.xml b/source/previews/PA-exp-modeling-D.xml
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In Desmos, define
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- Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
+ Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
- Consider a right triangle that has one leg of length
diff --git a/source/previews/PA-trig-right-D.xml b/source/previews/PA-trig-right-D.xml
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diff --git a/source/previews/PA-trig-tangent-D.xml b/source/previews/PA-trig-tangent-D.xml
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diff --git a/source/previews/doenet/PA-changing-aquarium-D.doenetml b/source/previews/doenet/PA-changing-aquarium-D.doenetml
new file mode 100644
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+
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+ Suppose that a rectangular aquarium is being filled with water. The tank is
+ What are some different quantities that are changing in this scenario?
+
+ Both the
+
+ After
+
+ At this moment, how deep is the water?
+
+
+ How much water is in the tank and how deep is the water after
+
+ After
+
+ How long will it take for the tank to be completely full?
+
+
+ How much water is in a full tank?
+ Let the height function for a ball tossed vertically be given by
+ We will explore some different ways of combining functions.
+
+ First, consider the functions
+ Let
+ Let
+ Now consider the functions The first piece of The first piece of
+ Calculate exactly:
+ Let
+ Note that
+ Calculate exactly:
+ Let
+ We have reproduced the graph of The first piece of The first piece of
+ Let
+ Let
+
+
+ In the introductory example with
+ Let
+
+
+ Suppose that
+
+ The result of composing
+ Use the equation
+ If we hear snowy tree crickets chirping at a rate of
+
+ If the outside temperature is
+
+ Is the model valid for determining the number of chirps one should hear when the outside temperature is
+
+ Suppose that in the morning an observer hears
+
+ What temperature corresponds to
+ What temperature corresponds to
+ Dolbear's Law is known to be accurate for temperatures from
+ What is the fewest number of chirps per minute an observer could expect to hear?
+ What is the greatest number of chirps per minute an observer could expect to hear?
+ Recall that
+ Solve the equation
+ The first step in solving the equation
+ The second step in solving the equation
+ Note that the equation
+ Find the simplest expression that you can for the composite function
+
+ Find the simplest expression that you can for the composite function
+
+ Complete the following sentences to explain why the functions
+ The function
+ Then the function
+ Similarly, the function
+ Let
+
+
+
+ Let
+ Determine
+
+
+
+ Consider the function
+ Determine
+
+
+
+ Note that in each of the three examples above, the functions involved were
+ For the function
+
+
+
+
+ Does your answer to
+ A water balloon is tossed vertically from a fifth story window. Its height,
+ Complete the table of function values below. For example,
+ Now use the values you computed to calculate
+ Complete the following sentences to record some observations about the function
+ The function
+ When does the water balloon land on the ground?
+ What is the average velocity of the water balloon in the final second before it lands?
+ What is the average velocity of the water balloon on the interval
+ We are going to explore transformations of a familiar quadratic function,
+ First, move the slider for
+ Set the value of the slider to
+ Which of the following observations are true for
+ Next, move the slider for
+ Set the value of the slider to
+ Which of the following observations are true for
+ Third, move the slider for
+ Set the value of the slider to
+ Which of the following observations are true for
+ Finally, change the function entered below and explore the sliders above again for this new function. Do any of your selected choices change when the function we are comparing to has changed? You can come up with your own functions to try, but some good ones to try that will fit in the window nicely could be
+
+ When
+ Drag the point on the unit circle to the location where
+ What is the exact value of
+ What is the exact value of
+ Complete the following table with the exact values of
+ Use the patterns you observe above to answer the following questions.
+
+ What is the exact value of
+ What is the exact value of
+ Give four different values of
+ Let
+ Answer all of the questions below without using a graph; after answering, a graph will appear and you'll either confirm or reflect on your answers using a graph. Note that there could be more than one correct answer to some questions.
+
+ A simplified version of the ferris wheel scenario pictured in Figure 2.1.1 has been reproduced below.
+
+ Assume that the height,
+ Recall that the circumference,
+ What is the radius of the ferris wheel?
+ How high is the highest point on the ferris wheel?
+ How high is the cab after it has traveled
+ How much distance along the circle has the cab traversed at the moment it first reaches a height of
+ Complete the following sentences.
+
+ The cab's height
+ The cab's distance traveled
+ In the following figure there are 24 equally spaced points on the unit circle. Since the circumference of the unit circle is
+ Move the large square point to each of the points in the remainder of the top half of the circle and enter the distance traveled along the circle counterclockwise from the point
+ When you have entered the correct distance for the selected point and hit enter or clicked outside the box, the distance traveled will appear on the graph near that point.
+
+
+ Hit Check Work when all of the correct distances appear for the top half of the circle and
+Continuing around the circle counterclockwise after
+
+ Which distance along the unit circle corresponds to
+ Which distance along the unit circle corresponds to
+ One way to measure angles is connected to the arc length along a circle. For an angle whose vertex is at
+ In the graph on the right, drag the square point so that an angle of
+ In the graph on the right, drag the square point so that an angle of
+ What is the radian measure that corresponds to a
+ The functions
+ Use the slider to find a value of
+ When
+ Use the slider to find a value of
+ When
+ Use the slider to find a value of
+ When
+ Below is another graph and slider, where now you are the one choosing the target function.
+
+ Enter a number for
+ When
+ When
+ When
+ Do you think you would be able to find a value of
+ Suppose that at age
+ Let
+ Determine
+
+
+
+
+ Note that if a quantity depreciates
+
+
+
+
+ Based on the patterns in your computations in parts a. and b., determine formulas for
+
+
+ The graphs of
+ Complete the sentence with some observations about the behavior of the two functions.
+
+ Even though both functions had the same form,
+ What else do you notice and wonder?
+
+ Let
+ Complete the following table to generate certain values of
+ We can see that the function
+ Since
+
+
+ In the following questions, we investigate how
+ Write
+
+ Enter the simplest possible way to write each of the expressions below.
+
+
+ Select the reason why each of the following equalities is true.
+
+
+
+
+ Putting it all together,
+
+ Suppose that
+ where the missing entries are:
+ In conclusion,
+ The graph below shows the function
+ All of the following situations contain expressions which can be used to model temperature or population growth. In each situation, we will solve for the exact value of various unknown quantities.
+
+ Below is an image of a right triangle whose sides are labeled
+ We will complete a sketch of a right triangle with one leg of length
+ First, determine the exact values of the sides
+
+
+ After answering all the questions in part a. correctly, you now have a correctly labeled right triangle meeting the specified conditions.
+
+ What is the exact value of
+
+ What special angle from the unit circle is
+
+ Use your answer to c. to rewrite your equation from b. using the arcsine function in the form
+
+ Consider the plot of the standard cosine function in the following figure along with the emphasized portion of the graph on
+ Let
+
+
+ We can see from the graph that
+ This means that
+ We know that
+
+ Determine the exact values of each of the quantities below.
+
+
+
+
+
+ What follows is
+ In each of the situations, you will end up with an image of a right triangle that satisfies the given conditions, and you will determine the requested missing information in the triangle. Assume that all angles are being considered in radian measure.
+
+ Determine the values of
+
+
+ First, drag the point below until you have a right triangle with hypotenuse of length
+ Once you have found such a triangle, use the coordinates of the point on the unit circle to determine and enter the lengths of the two legs.
+
+ Determine the values of
+
+
+
+ First, determine the values of the sides
+
+
+
+ Then determine the exact measures of the two non-right angles.
+
+
+ Through the following questions, we work to understand the special values and overall behavior of the tangent function.
+
+ Use the unit circle below (not a computational device) to find the exact value of
+ Move the square point to each of the above angles and an answer box will appear. Enter a simplified exact expression, not a decimal approximation.
+
+
+ What are three other input values
+ Drag the point to the approximate location of
+
+ A table of values appears below, including the values from the angles asked about in the first graph above after you've answered them correctly.
+
+ Moreover, a graph of the values appears below, and you can click to show the function
+ Use the graph and your work above to answer the following:
+
+
+
+
- For a function
- For a function
- The average rate of change of a function on an interval gives us an excellent way to describe how the function behaves, on average. For instance, if we compute
- Finally, we can even use the average rate of change of a function to predict future behavior. Since the population was changing on average by
- Let
- Similarly, we say that
- For a function
- How can we create new functions by adding, subtracting, multiplying, or dividing given functions?
+ How can we create new functions by adding, subtracting, multiplying, or dividing given functions?
- We can work similarly with functions. Indeed, we have already seen a sophisticated way to combine two functions to generate a new, related function through composition. If
@@ -44,6 +44,7 @@
A familiar and important function that is defined piecewise
is the absolute value function:
The absolute value of a real number, denoted by
- Just as we can generate a new number by adding, subtracting, multiplying, or dividing two given numbers, we can generate a new function by adding, subtracting, multiplying, or dividing two given functions. For instance, if we know formulas, graphs, or tables for functions
A piecewise function is a function whose formula consists of at least two different formulas in such a way that which formula applies depends on where the input falls in the domain. For example, given two functions
- If
To think about the interval
- By definition, we know that
+ By definition, we know that
- In
Because the expression
- For a mathematical model, we often seek an algebraic formula that captures observed behavior accurately and can be used to predict behavior not yet observed. For the data in
- The mathematical concept of a function
@@ -82,7 +83,7 @@
Tables and graphs are particularly valuable ways to characterize and represent functions. For the current example, we summarize some of the data the Dolbear function generates in Graph of data from the function
+
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diff --git a/source/previews/doenet/PA-changing-aroc-D.doenetml b/source/previews/doenet/PA-changing-aroc-D.doenetml
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diff --git a/source/previews/doenet/PA-changing-composite-D.doenetml b/source/previews/doenet/PA-changing-composite-D.doenetml
new file mode 100644
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The second piece of
The third piece of
The second piece of
+ Calculate exactly:
+
+
+ Calculate exactly:
+
+
Note that a fraction is undefined when the denominator is
The second piece of
The third piece of
The second piece of
+
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diff --git a/source/previews/doenet/PA-changing-functions-crickets-D.doenetml b/source/previews/doenet/PA-changing-functions-crickets-D.doenetml
new file mode 100644
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+ Dolbear's Law
.
+
+
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diff --git a/source/previews/doenet/PA-changing-inverse-F-C-D.doenetml b/source/previews/doenet/PA-changing-inverse-F-C-D.doenetml
new file mode 100644
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diff --git a/source/previews/doenet/PA-changing-linear-3-ex-D.doenetml b/source/previews/doenet/PA-changing-linear-3-ex-D.doenetml
new file mode 100644
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diff --git a/source/previews/doenet/PA-changing-quadratic-D.doenetml b/source/previews/doenet/PA-changing-quadratic-D.doenetml
new file mode 100644
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diff --git a/source/previews/doenet/PA-changing-transformations-quadratic-D.doenetml b/source/previews/doenet/PA-changing-transformations-quadratic-D.doenetml
new file mode 100644
index 00000000..1693bc9d
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diff --git a/source/previews/doenet/PA-circular-sine-D.doenetml b/source/previews/doenet/PA-circular-sine-D.doenetml
new file mode 100644
index 00000000..e7f6afce
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+++ b/source/previews/doenet/PA-circular-sine-D.doenetml
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+
+
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+ You can move it again afterwards.
+
+ You can move it again afterwards.
+
+ You can move it again afterwards.
+
+
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diff --git a/source/previews/doenet/PA-circular-sinusoidal-D.doenetml b/source/previews/doenet/PA-circular-sinusoidal-D.doenetml
new file mode 100644
index 00000000..c858dfb6
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diff --git a/source/previews/doenet/PA-circular-unit-circle-D.doenetml b/source/previews/doenet/PA-circular-unit-circle-D.doenetml
new file mode 100644
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+
+
+
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+
+
+
+
+
+ Or, you can recall that the total distance around a circle with radius
+
+
+
+
+
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diff --git a/source/previews/doenet/PA-exp-growth-D.doenetml b/source/previews/doenet/PA-exp-growth-D.doenetml
new file mode 100644
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diff --git a/source/previews/doenet/PA-exp-log-D.doenetml b/source/previews/doenet/PA-exp-log-D.doenetml
new file mode 100644
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+
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+powers of 10
function, which is given by
+
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diff --git a/source/previews/doenet/PA-exp-log-properties-D.doenetml b/source/previews/doenet/PA-exp-log-properties-D.doenetml
new file mode 100644
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+
+
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says the exact same thing as writing
. In words, where
+
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+
+
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diff --git a/source/previews/doenet/PA-trig-inverse-D.doenetml b/source/previews/doenet/PA-trig-inverse-D.doenetml
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diff --git a/source/previews/doenet/PA-trig-right-D.doenetml b/source/previews/doenet/PA-trig-right-D.doenetml
new file mode 100644
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plays. In particular, to understand the expression for
we can also use the equivalent notation
to indicate that Dolbear's Law takes an input of
to indicate that a certain temperature,
+
When a point such as
.
@@ -134,7 +135,7 @@
For most important concepts in mathematics, the mathematical community decides on formal definitions to ensure that we have a shared language of understanding. In this text, we will use the following definition of the term function
.
-
- Let
Graph of the function
- For this abstract function, its domain is all real numbers
since we may input any real number all real numbers.
Finally, from the graph and the data, we observe that the largest possible output of the function
indicates that there is no left-hand bound on the interval.all real numbers
since we may input any real number all real numbers.
Finally, from the graph and the data, we observe that the largest possible output of the function
indicates that there is no left-hand bound on the interval.
@@ -281,13 +282,13 @@
Graph of the model
- To this point in our discussion of functions, we have mostly focused on what the function process may model and what the domain, codomain, and range of a model or abstract function are. It is also important to take note of another part of
- Solution. The relationship between
. Said differently, if a relationship or process ever associates a single input with two or more different outputs, the process cannot be a function.
+ To this point in our discussion of functions, we have mostly focused on what the function process may model and what the domain, codomain, and range of a model or abstract function are. It is also important to take note of another part of
. Said differently, if a relationship or process ever associates a single input with two or more different outputs, the process cannot be a function.
- When we use a computing device such as Desmos to graph a function
A visual representation of the data in
- Sometimes it is possible to use variables and one or more equations to connect quantities that are changing in tandem. In the aquarium example from the preview activity, we can observe that the volume,
The conical tank, partially filled.
- If we consider the conical tank discussed in
- With the equation Plotting Plotting
- Let
- When a given function has an inverse function, it allows us to express the same relationship from two different points of view. For instance, if
- If
@@ -249,7 +250,7 @@
- Taking
- The functions
- A function
- Let's suppose we know that a function
@@ -152,10 +153,10 @@
The slope-intercept form of a line's equation.
+
A special case arises when the known point on a line satisfies
of the line.
- For the line with slope
Since linear functions are defined by the property that their average rate of change is constant, linear functions perfectly model quantities that change at a constant rate. In context, we can often think of slope as a rate of change; analyzing units carefully often yields significant insight.
- +
@@ -232,7 +233,7 @@
The linear Dolbear function with slope
Like with the Dolbear function, it is often useful to write a linear function (whose output is called
After linear functions,
quadratic functions are arguably the next simplest functions in mathematics.
@@ -48,6 +48,7 @@
- Because quadratic functions are familiar to us, we will quickly restate some of their important known properties. + Because quadratic functions are familiar to us, we will quickly restate some of their important known properties.
- Every quadratic function has a
+
In addition, every quadratic function has a symmetric graph that either always curves upward or always curves downward. The graph opens upward if and only if
- The quadratic function
- Note particularly that due to symmetry, the vertex of a quadratic function lies halfway between its
- Next, observe that the vertex of
+ Next, observe that the vertex of
- Finally, the form
+
+
In
- A key closing observation here is that the fact the parabola
diff --git a/source/sec-changing-transformations.xml b/source/sec-changing-transformations.xml
index c631d0b9..fe37bfe4 100755
--- a/source/sec-changing-transformations.xml
+++ b/source/sec-changing-transformations.xml
@@ -31,25 +31,27 @@
- In our preparation for calculus, we aspire to understand functions from a wide range of perspectives and to become familiar with a library of basic functions. So far, two basic families of functions we have considered are linear functions and quadratic functions, the simplest of which are
Informally, a transformation
+
In
- We begin by summarizing two of our findings in
- As we found in our Desmos explorations in the preview activity, is especially helpful to see the effects of vertical translation dynamically.
+ As we found in our Desmos explorations in the preview activity, is especially helpful to see the effects of vertical translation dynamically.
- Move the slider
In a vertical translation, the graph of
- In
@@ -110,7 +112,7 @@
- Again, it's instructive to see the effects of horizontal translation dynamically.
+ Again, it's instructive to see the effects of horizontal translation dynamically.
- Move the slider by clicking and dragging on the red point to see how changing
Overall, we have the following general principle.
@@ -139,7 +141,7 @@
Given a function
We emphasize that in the horizontal translation
- As with vertical and horizontal translation, it's particularly instructive to see the effects of vertical scaling in a dynamic way.
+ As with vertical and horizontal translation, it's particularly instructive to see the effects of vertical scaling in a dynamic way.
- Move the slider by clicking and dragging on the red point to see how changing
We summarize and generalize our observations from
- add
- Continuing, we now consider the function
- While there are some transformations that can be executed in either order (such as a combination of a horizontal translation and a vertical translation, as seen in part (b) of
- It is often useful to follow one particular point through a sequence of transformations. In
@@ -104,18 +105,18 @@
- Move the slider by clicking and dragging on the red point to see how changing
By experimenting with the slider, we gain an intuitive sense for how the value of
- We can also understand this from the perspective of function composition. To evaluate
- Given any circular periodic function for which the midline, amplitude, period, and an anchor point are known, we can find a corresponding formula for the function of the form
+ Given any circular periodic function for which the midline, amplitude, period, and an anchor point are known, we can find a corresponding formula for the function of the form
- If we pick any point
- To study the circular functions generated by the unit circle, we will also animate a point and let it traverse the circle. Starting at
- As seen in
- Since there are
- Our work in
- In any circle of radius
- For instance,
- Initially, it's important to note that
- If we compare the graphs and some selected outputs of each function, as in
- It follows that the function
- Linear functions have constant average rate of change and model many important phenomena. In other settings, it is natural for a quantity to change at a rate that is proportional to the amount of the quantity present. For instance, whether you put $
@@ -52,7 +52,7 @@
- If we repeat our computations for the second year, we observe that
+ If we repeat our computations for the second year, we observe that
Because we will be frequently interested in functions such as
We explore the properties of functions of form
- Recall that a function is increasing on an interval if its value always increases as we move from left to right. Similarly, a function is decreasing on an interval provided that its value always decreases as we move from left to right.
+ Recall that a function is increasing on an interval if its value always increases as we move from left to right. Similarly, a function is decreasing on an interval provided that its value always decreases as we move from left to right.
- If we consider an exponential function
An additional trend is apparent in the graphs in
- For an exponential function of the form
diff --git a/source/sec-exp-log-properties.xml b/source/sec-exp-log-properties.xml
index a702ada1..4248a131 100755
--- a/source/sec-exp-log-properties.xml
+++ b/source/sec-exp-log-properties.xml
@@ -39,6 +39,7 @@
A population of bacteria cells is growing at a rate proportionate to the number of cells present at a given time
@@ -251,9 +252,9 @@
In
+
More formally, recall that a function
- Given a positive real number
- The base-
- In the notation of logarithms, we can now update our earlier observations with the functions
@@ -153,7 +154,7 @@
- Given a positive real number
- In
Determine the exact value of
Solution. Since we want
@@ -76,7 +76,7 @@
- In one sense, the data looks exponential: the points appear to lie on a curve that is always decreasing and decreasing at an increasing rate. However, we know that the function can't have the form
- For the increasing function
@@ -173,7 +174,7 @@
- To represent these two common phenomena with exponential functions
@@ -223,7 +224,7 @@
- The function
- It's an important skill to be able to look at an exponential function of the form
We've seen that exponential functions can be used to model several different important phenomena, such as the growth of money due to continuously compounded interest, the decay of radioactive quanitities, and the temperature of an object that is cooling or warming due to its surroundings. From initial work with functions of the form
@@ -34,7 +34,7 @@
- While the original trigonometric functions take a particular angle as input and provide an output that can be viewed as the ratio of two sides of a right triangle, the inverse trigonometric functions take an input that can be viewed as a ratio of two sides of a right triangle and produce the corresponding angle as output. Indeed, it's imperative to remember that statements such as
+ While the original trigonometric functions take a particular angle as input and provide an output that can be viewed as the ratio of two sides of a right triangle, the inverse trigonometric functions take an input that can be viewed as a ratio of two sides of a right triangle and produce the corresponding angle as output. Indeed, it's imperative to remember that statements such as
We can now find the remaining leg's length and the remaining angle's measure. If we let
- Anytime we know two side lengths in a right triangle, we can use one of the inverse trigonometric functions to determine the measure of one of the non-right angles. For instance, if we know the values of
- Let
- The restricted cosine function, ADD ALT TEXT TO THIS IMAGE
- Let
- Finally, we develop an inverse function for a restricted version of the tangent function. We choose the domain
- Let
- For any
- For any
- For any real number
The domain of
The domain of
- By changing our perspective slightly, we can see that it is equivalent to think of the values of the sine and cosine function as representing the lengths of legs in right triangles. Specifically, given a central angle
- In
- Consider a right triangle in which one of the non-right angles is
@@ -225,7 +226,7 @@
- In
-
@@ -241,7 +242,7 @@
Because the ratio of numbers closer and closer to
+
Plotting the data in the table along with the expected asymptotes and connecting the points intuitively, we see the graph of the tangent function in
- For the function
@@ -310,15 +311,15 @@
- Using the perspective that
Once we know the river's width, we can use the Pythagorean theorem or the sine function to determine the distance from
-
-
notation and focus on the starting value of each interval, viewing the resulting average rate of change,
@@ -179,7 +180,7 @@
bends down
is apparently connected to the fact that its average rate of change decreases as we move left to right. By contrast, for a quadratic function that bends up
, we can show that its average rate of change increases as we move left to right (see bends down
is apparently connected to the fact that its average rate of change decreases as we move left to right. By contrast, for a quadratic function that bends up
, we can show that its average rate of change increases as we move left to right (see parent
function as the most fundamental member of a family of functions, as well as how other similar but more complicated functions are the result of transforming the parent function.
+ In our preparation for calculus, we aspire to understand functions from a wide range of perspectives and to become familiar with a library of basic functions. So far, two basic families of functions we have considered are linear functions and quadratic functions, the simplest of which are parent
function as the most fundamental member of a family of functions, as well as how other similar but more complicated functions are the result of transforming the parent function.
exponential
, understanding that technically these are vertical stretches of exponential functions according to growth factor
of exponential growth
, wherease if exponential decay
.
undo
one another's respective processes. In other words, the process of the function
to denote the base-
to denote the base-
, while the second says
. Similarly,
+ each say the same thing from two different perspectives. The first says
, while the second says
. Similarly,
the power to which we raise
. That is, the base-the power to which we raise
. That is, the base-
to denote the natural logarithm of
to denote the natural logarithm of
. We know that it is equivalent to say
+ This last equation says
. We know that it is equivalent to say
as
as
as
as
-
+
@@ -283,7 +284,7 @@
- What are three other input values
- Complete each of the following statements with an appropriate number or the symbols
@@ -34,7 +34,7 @@
- Determine a formula for the function
- If we start with a small positive value for
@@ -22,10 +22,10 @@
- What is the largest number of distinct points at which
- Recall from the definition of a polynoimal function what we mean by a
- A degree 4 polynomial can have
diff --git a/source/previews/PA-poly-rational.xml b/source/previews/PA-poly-rational.xml
index 421c833e..a0c3ca94 100755
--- a/source/previews/PA-poly-rational.xml
+++ b/source/previews/PA-poly-rational.xml
@@ -11,12 +11,12 @@
-
A drug company estimates that to produce a new drug,
- it will cost $5 million in startup resources, and that once they reach production, each gram of the drug will cost $2500 to make.
+ it will cost
- The drug company needs to sell the drug at a price of more than $2500 per gram in order to at least break even. To investigate how they might set prices, they first consider what their average cost per gram is. What is the total cost of producing
- Explain why another formula for
- This activity is based on p. 457ff in Functions Modeling Change, by Connally et al.
+ This activity is based on p. 457ff in Functions Modeling Change, 5th edition, by Connally et al.
diff --git a/source/previews/doenet/PA-poly-infty-D.doenetml b/source/previews/doenet/PA-poly-infty-D.doenetml
new file mode 100644
index 00000000..cec9578c
--- /dev/null
+++ b/source/previews/doenet/PA-poly-infty-D.doenetml
@@ -0,0 +1,60 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Complete each of the following statements with an appropriate number or the symbols
+
+
+
+
+
+
+
+ A piece of cardboard that is
+ As shown in the diagram, let
+
+
+
+ We know that the volume of a rectangular box is given by
+
+
+
+
+ Hit Check Work when you have adjusted the sliders so that the graph crosses the
+ Hit Check Work when you have adjusted the sliders so that the graph crosses the
+ Hit Check Work when you have adjusted the sliders so that the graph crosses the
+ Recall from the definition of a polynoimal function what we mean by a
+ Hit Check Work when you have adjusted the sliders so that the graph shows
+ It is also possible to adjust the sliders so that the graph has exactly
+ We say that a function has a
+ Recall that
+ Experiment with the sliders, and hit Check Work when
+ Experiment with the sliders, and hit Check Work when
+ What other numbers of turning points are possible for
+ What long-range behavior is possible for
+ Experiment with the sliders, and hit Check Work when
+ Experiment with the sliders, and hit Check Work when
+ Click on the box below to plot
+
+ It also means that the long-range behavior of
+ Can you see how this behavior affects the possible number of turning points from part b.?
+
+ A drug company estimates that to produce a new drug, it will cost
+ Determine a formula for a function
+
+ The drug company needs to sell the drug at a price of more than
+
+
+
+
+ Our computations in b. and c. naturally lead us to define the
+ The average cost per gram of producing
+ What can you say about the long-range behavior of
+
+ In the context of this scenario, this means
+ Consider the rational function
+
+
+ Type
+
+ Complete the sentences below to explain why
+ As
+ As
+ As
+ Finally, the graph of
+ Can you see all the behavior we just discussed, or only some of it? Remember that you can zoom in and out using the "+" and "-" in the lower right corner of the graph, and that the "O" returns to the original view.
+
+ Below is an image of a right triangle whose sides are labeled
+ We will complete a sketch of a right triangle with hypotenuse of length
+ First, determine the exact values of the sides
+
+
+ After answering all the questions in part a. correctly, you now have a correctly labeled right triangle meeting the specified conditions.
+
+ Determine the exact value of each of the six trigonometric functions evaluated at
+ What are the exact and approximate measures of the two non-right angles in the triangle?
+
+
+
- In
- When observing a pattern in the values of a function that correspond to letting the inputs get closer and closer to a fixed value or letting the inputs increase or decrease without bound, we are often interested in the behavior of the function
@@ -95,8 +96,8 @@
If the value of infinity
.
+
+
\ No newline at end of file
diff --git a/source/previews/doenet/PA-poly-polynomial-applications-D.doenetml b/source/previews/doenet/PA-poly-polynomial-applications-D.doenetml
new file mode 100644
index 00000000..31d47761
--- /dev/null
+++ b/source/previews/doenet/PA-poly-polynomial-applications-D.doenetml
@@ -0,0 +1,155 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Note that when we write
+ Note that when we write
+ Note that when we write
+
\ No newline at end of file
diff --git a/source/previews/doenet/PA-poly-polynomials-D.doenetml b/source/previews/doenet/PA-poly-polynomials-D.doenetml
new file mode 100644
index 00000000..d6453656
--- /dev/null
+++ b/source/previews/doenet/PA-poly-polynomials-D.doenetml
@@ -0,0 +1,154 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ average cost per gram
function,
+
\ No newline at end of file
diff --git a/source/sec-poly-infty.xml b/source/sec-poly-infty.xml
index 7c7f2915..98b3ce8d 100755
--- a/source/sec-poly-infty.xml
+++ b/source/sec-poly-infty.xml
@@ -36,11 +36,11 @@
in the limit
. In either case, we are considering an infinite collection of inputs that are themselves following a pattern, and we ask the question how can we expect the function's output to behave if we continue?
+ When observing a pattern in the values of a function that correspond to letting the inputs get closer and closer to a fixed value or letting the inputs increase or decrease without bound, we are often interested in the behavior of the function in the limit
. In either case, we are considering an infinite collection of inputs that are themselves following a pattern, and we ask the question how can we expect the function's output to behave if we continue?
- We'll also often consider the surface area of a three-dimensional container. For a rectangular box with side lengths of sides
. If we think of cutting the cylinder vertically and unfurling it, the resulting figure is a rectangle whose dimensions are the height of the cylinder,
The main issue to realize is that the form of the curve depends on a special family of cubic polynomials:
- Polynomials arise naturally in the study of problems involving the volume and surface area of three-dimensional containers such as boxes and cylinders because these formulas fundamentally involve sums and products of variables. For instance, the volume of a cylinder is
Polynomial functions can be used to approximate non-polynomial curves and functions in many different ways. One example is found in cubic Bezier curves which use a collection of control points to enable the user to manipulate curves to pass through select points in such a way that the curve first travels in a certain direction. Another example is in the remarkable approximation of non-polynomial functions like the sine function, as given by
Given real numbers
- We know that each of the power functions
- The Zero Product Property
- To see the impact of repeated factors, we examine a collection of degree
is repeated
is repeated
@@ -247,8 +248,8 @@
- If we next let
- What does a sign chart reveal about the behavior of a rational function and how do we develop a sign chart from a given formula? + What does a sign chart reveal about the behavior of a rational function and how do we develop a sign chart from a given formula?
- Because any rational function is the ratio of two polynomial functions, it's natural to ask questions about rational functions similar to those we ask about polynomials. With polynomials, it is often helpful to know where the function's value is zero. In a rational function
@@ -44,6 +44,7 @@
- The key observations regarding zeros, vertical asymptotes, and holes in
- On the interval
- If a rational function
- By writing a rational function's numerator in factored form, we can generate a sign chart for the function that takes into account all of the zeros and vertical asymptotes of the function, which are the only points where the function can possibly change sign. By testing
- Like with polynomial functions, we are interested in such natural questions as + Like with polynomial functions, we are interested in such natural questions as
@@ -116,7 +117,7 @@
In both situations (a) and (b), the value of
- Neglecting any scrap, the amount of material it takes to construct the container is its surface area, which we know to be
+ Neglecting any scrap, the amount of material it takes to construct the container is its surface area, which we know to be
- Two reasons that rational functions are important are that they arise naturally when we consider the average rate of change on an interval whose length varies and when we consider problems that relate the volume and surface area of three-dimensional containers when one of those two quantities is constrained. + Two reasons that rational functions are important are that they arise naturally when we consider the average rate of change on an interval whose length varies and when we consider problems that relate the volume and surface area of three-dimensional containers when one of those two quantities is constrained.
- But we could also view
-
In addition, we observe that as
+
Plotting the data in the table along with the expected asymptotes and connecting the points intuitively, we see the graph of the secant function in
- For the function
@@ -306,7 +307,7 @@ \cos^2(\theta) + \sin^2(\theta) = 1 .
- +
@@ -317,14 +318,14 @@
There are two related Pythagorean identities that involve the tangent, secant,
cotangent, and cosecant functions, which we can derive from the fundamental trigonometric identity by dividing both sides by either
- The secant, cosecant, and cotangent functions are respectively defined as the reciprocals of the cosine, sine, and tangent functions. That is,
+ The secant, cosecant, and cotangent functions are respectively defined as the reciprocals of the cosine, sine, and tangent functions. That is,
| - - | -
| - - | -
|
- - |
-
| - - | -
| - - | -
|
- - |
-
| - - | -
| - - | -
|
- - |
-
| + + | +
| + + | +
|
+ + |
+
| + + | +
| + + | +
|
+ + |
+
| + + | +
| + + | +
|
+ + |
+
-
- Determine On the interval
.
-
- On which interval is there more total change in the soda's temperature:
- What can you observe about when the soda's temperature appears to be changing most rapidly? -
-
- Estimate the soda's temperature when
- Exercise Answer -
-Change on
The soda's temperature is changing most rapidly at the beginning (when
The rate of change on
- The position of a car driving along a straight road at time
The graph of
-
- In everyday language,
- describe the behavior of the car over the provided time interval.
- In particular,
- carefully discuss what is happening on each of the time intervals
- Compute the average rate of change of
appropriately, and include units on each quantity.
-
- On the graph of
- Is there a time interval on which the car's average velocity is
- Is there ever a time interval when the car is going in reverse? Why or why not? -
-- Exercise Answer -
-Read from the graph: describe behavior on each interval. Where the graph rises steeply, the car moves quickly; where flat, the car is stopped; where the slope is gentler, the car moves more slowly.
From the graph:
On the graph, sketch line segments connecting
An average velocity of
If the position graph is always non-decreasing, the car never goes in reverse. Reverse motion would correspond to a portion of the graph with negative slope (decreasing
- Consider an inverted conical tank (point down) whose top has a radius of
-
- In everyday language, describe how you expect the height function
- For the height function
- Again working with the height function, can you determine an interval
- Now consider the volume function,
- Exercise Answer -
-As the conical tank fills, the cone widens, so equal amounts of water produce smaller increases in height. Therefore
Using
Yes. For intervals
Since
+ A cold can of soda is removed from a refrigerator. Its temperature
+
+ Determine On the interval
.
+
+ On which interval is there more total change in the soda's temperature:
+ What can you observe about when the soda's temperature appears to be changing most rapidly? +
+
+ Estimate the soda's temperature when
+ Exercise Answer +
+Change on
The soda's temperature is changing most rapidly at the beginning (when
The rate of change on
+ The position of a car driving along a straight road at time
The graph of
+
+ In everyday language,
+ describe the behavior of the car over the provided time interval.
+ In particular,
+ carefully discuss what is happening on each of the time intervals
+ Compute the average rate of change of
appropriately, and include units on each quantity.
+
+ On the graph of
+ Is there a time interval on which the car's average velocity is
+ Is there ever a time interval when the car is going in reverse? Why or why not? +
++ Exercise Answer +
+Read from the graph: describe behavior on each interval. Where the graph rises steeply, the car moves quickly; where flat, the car is stopped; where the slope is gentler, the car moves more slowly.
From the graph:
On the graph, sketch line segments connecting
An average velocity of
If the position graph is always non-decreasing, the car never goes in reverse. Reverse motion would correspond to a portion of the graph with negative slope (decreasing
+ Consider an inverted conical tank (point down) whose top has a radius of
+
+ In everyday language, describe how you expect the height function
+ For the height function
+ Again working with the height function, can you determine an interval
+ Now consider the volume function,
+ Exercise Answer +
+As the conical tank fills, the cone widens, so equal amounts of water produce smaller increases in height. Therefore
Using
Yes. For intervals
Since
- Let
-
-
-
-
-
-
- Exercise Answer -
-
- Consider the functions
The graph of a piecewise function,
The graph of a piecewise function,
-
- Determine a piecewise formula for the function
- Determine a piecewise formula for the function
- Determine each of the following quantities or explain why they are not defined. -
--
-
-
-
-
- Exercise Answer -
-Read the graph of
Similarly, read the graph of
With formulas for
- One of the most important principles in the study of changing quantities is found in the relationship between distance,
- average velocity, and time.
- For a moving body traveling on a straight-line path at an average rate of
- In the Ironman Triathlon,
- competitors swim
- She swims at an average rate of
- Her transition from swim to bike takes
- She bikes at an average rate of
- Her transition from bike to run takes just over
- She runs at an average rate of
- In the questions that follow, - assume for the purposes of the model that the triathlete swims, bikes, - and runs at essentially constant rates - (given by the average rates stated above). -
-- Determine the time the swimmer exits the water. - Report your result in hours. -
-- Likewise, determine the time the athlete gets off her bike, - as well as the time she finishes the race. -
-- List 5 key points in the form (time, distance): - when exiting the water, when starting the bike, - when finishing the bike, when starting the run, - and when finishing the run. -
-- What is the triathlete's average velocity over the course of the entire race? - Is this velocity the average of her swim velocity, bike velocity, and run velocity? Why or why not? -
-
- Determine a piecewise function
- Sketch a carefully labeled graph of the triathlete's distance traveled as a function of time on the axes provided. - Provide clear scale and note key points on the graph. -
- -ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- Sketch a possible graph of the triathete's velocity,
- Exercise Answer -
-The triathlete exits the water after the swim at
The bike finishes at
Key points: exits water at
See graphs below.
+ Let
+
+
+
+
+
+
+ Exercise Answer +
+
+ Consider the functions
The graph of a piecewise function,
The graph of a piecewise function,
+
+ Determine a piecewise formula for the function
+ Determine a piecewise formula for the function
+ Determine each of the following quantities or explain why they are not defined. +
++
+
+
+
+
+ Exercise Answer +
+Read the graph of
Similarly, read the graph of
With formulas for
+ One of the most important principles in the study of changing quantities is found in the relationship between distance,
+ average velocity, and time.
+ For a moving body traveling on a straight-line path at an average rate of
+ In the Ironman Triathlon,
+ competitors swim
+ She swims at an average rate of
+ Her transition from swim to bike takes
+ She bikes at an average rate of
+ Her transition from bike to run takes just over
+ She runs at an average rate of
+ In the questions that follow, + assume for the purposes of the model that the triathlete swims, bikes, + and runs at essentially constant rates + (given by the average rates stated above). +
++ Determine the time the swimmer exits the water. + Report your result in hours. +
++ Likewise, determine the time the athlete gets off her bike, + as well as the time she finishes the race. +
++ List 5 key points in the form (time, distance): + when exiting the water, when starting the bike, + when finishing the bike, when starting the run, + and when finishing the run. +
++ What is the triathlete's average velocity over the course of the entire race? + Is this velocity the average of her swim velocity, bike velocity, and run velocity? Why or why not? +
+
+ Determine a piecewise function
+ Sketch a carefully labeled graph of the triathlete's distance traveled as a function of time on the axes provided. + Provide clear scale and note key points on the graph. +
+ +ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ Sketch a possible graph of the triathete's velocity,
+ Exercise Answer +
+The triathlete exits the water after the swim at
The bike finishes at
Key points: exits water at
See graphs below.
- Use the given information about various functions to answer the following questions involving composition. -
- --
- Let functions
Plot of
Plot of
- Determine
- Again using the functions given in (a), can you determine a value of
- Let functions
- Determine
- For the functions
- Let
- For the function
- Exercise Answer -
-From the graphs:
From the table:
Domain of
- Recall Dolbear's function that defines temperature,
-
- -
- Solve the equation
- Say that
- How many chirps per minute do we expect when the outsidet temperature is
- Recall that the function that converts Fahrenheit to Celsius is
-
- Is it possible to write the chirp-rate
- Exercise Answer -
-Solving
Solving
Yes:
- For each of the following functions, find two simpler functions
-
-
-
-
-
- A spherical tank has radius
-
- Calculus can be used to show that the volume,
- We are given the fact that the tank is being filled in such a way that the height of the water rises at a constant rate of
- What are the domain and range of the function
- In (a) we observed that
- What are the domain and range of the function
- On the provided axes, sketch accurate graphs of
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- Why do each of the two graphs have their respective shapes? Write at least one sentence to explain each graph; refer explicitly to the shape of the tank and other information given in the problem. -
- -- Exercise Answer -
-Domain:
Since the height increases at a constant rate,
Domain:
Domain:
The graph of
+ Use the given information about various functions to answer the following questions involving composition. +
+ ++
+ Let functions
Plot of
Plot of
+ Determine
+ Again using the functions given in (a), can you determine a value of
+ Let functions
+ Determine
+ For the functions
+ Let
+ For the function
+ Exercise Answer +
+From the graphs:
From the table:
Domain of
+ Recall Dolbear's function that defines temperature,
+
+ +
+ Solve the equation
+ Say that
+ How many chirps per minute do we expect when the outsidet temperature is
+ Recall that the function that converts Fahrenheit to Celsius is
+
+ Is it possible to write the chirp-rate
+ Exercise Answer +
+Solving
Solving
Yes:
+ For each of the following functions, find two simpler functions
+
+
+
+
+
+ A spherical tank has radius
+
+ Calculus can be used to show that the volume,
+ We are given the fact that the tank is being filled in such a way that the height of the water rises at a constant rate of
+ What are the domain and range of the function
+ In (a) we observed that
+ What are the domain and range of the function
+ On the provided axes, sketch accurate graphs of
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ Why do each of the two graphs have their respective shapes? Write at least one sentence to explain each graph; refer explicitly to the shape of the tank and other information given in the problem. +
+ ++ Exercise Answer +
+Domain:
Since the height increases at a constant rate,
Domain:
Domain:
The graph of
- Consider an inverted conical tank (point down) whose top has a radius of
-
- Recall that the volume of a conical tank of radius
- On the provided axes, sketch possible graphs of both
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- What is the domain of the model
- It's possible to show that the formula for the function
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- Exercise Answer -
-The full volume is
The graph of
The domain of
The model
- A person is taking a walk along a straight path. Their velocity,
The velocity graph for a person walking along a straight path.
--
- What is the person's velocity when
- Are there any times when the person's velocity is exactly
- Describe the person's behavior on the time interval
- On which time interval does the person travel a farther distance:
- Exercise Answer -
-The values of
Any time the graph of
On the interval
The distance traveled is proportional to the area under the velocity curve (or its absolute value). Compare the areas under the graph on
- A driver of a new car periodically keeps track of the number of gallons of gas remaining in their car's tank, while simultaneously tracking the trip odometer mileage. Their data is recorded in the following table. Note that at mileages where they add fuel to the tank, they record the mileage twice: once before fuel is added, and once afterward. -
- -- Use the table to respond to the questions below. -
- --
- Can the amount of fuel in the gas tank,
- Does the car's fuel economy appear to be constant or does it appear to vary? Why? -
-- At what odometer reading did the driver put the most gas in the tank? -
-- Exercise Answer -
-No,
The fuel economy appears to be constant. Between
At
+ Consider an inverted conical tank (point down) whose top has a radius of
+
+ Recall that the volume of a conical tank of radius
+ On the provided axes, sketch possible graphs of both
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ What is the domain of the model
+ It's possible to show that the formula for the function
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ Exercise Answer +
+The full volume is
The graph of
The domain of
The model
+ A person is taking a walk along a straight path. Their velocity,
The velocity graph for a person walking along a straight path.
++
+ What is the person's velocity when
+ Are there any times when the person's velocity is exactly
+ Describe the person's behavior on the time interval
+ On which time interval does the person travel a farther distance:
+ Exercise Answer +
+The values of
Any time the graph of
On the interval
The distance traveled is proportional to the area under the velocity curve (or its absolute value). Compare the areas under the graph on
+ A driver of a new car periodically keeps track of the number of gallons of gas remaining in their car's tank, while simultaneously tracking the trip odometer mileage. Their data is recorded in the following table. Note that at mileages where they add fuel to the tank, they record the mileage twice: once before fuel is added, and once afterward. +
+ ++ Use the table to respond to the questions below. +
+ ++
+ Can the amount of fuel in the gas tank,
+ Does the car's fuel economy appear to be constant or does it appear to vary? Why? +
++ At what odometer reading did the driver put the most gas in the tank? +
++ Exercise Answer +
+No,
The fuel economy appears to be constant. Between
At
- Consider the functions
Plots of the graphs of
-
- Compute each of the following values exactly, or explain why they are not defined:
- From your work in (a), you know that the point
- On
- Exercise Answer -
-From the graph:
Since the graph of
Plot the six known points and sketch the complete graph of
- Consider an inverted conical tank that is being filled with water. The tank's radius is
The conical tank.
-Axes to plot
-
- Explain why the height,
- At what time is the water in the tank
- Suppose we think of the volume,
- Recall that the volume of a cone of radius
- Use the fact that
- Take the formula for
- Find the exact time that there is
- Exercise Answer -
-Since the water level rises at a constant rate of
At
Yes: as time increases, the volume strictly increases (more water is added continuously), so the function
Substituting
Solving
At
- Recall that in
-
- What familiar type of function is
- Determine an algebraic formula for
- What is the meaning of the statement
- Determine the average rate of change of
- Determine the average rate of change of
+ Consider the functions
Plots of the graphs of
+
+ Compute each of the following values exactly, or explain why they are not defined:
+ From your work in (a), you know that the point
+ On
+ Exercise Answer +
+From the graph:
Since the graph of
Plot the six known points and sketch the complete graph of
+ Consider an inverted conical tank that is being filled with water. The tank's radius is
The conical tank.
+Axes to plot
+
+ Explain why the height,
+ At what time is the water in the tank
+ Suppose we think of the volume,
+ Recall that the volume of a cone of radius
+ Use the fact that
+ Take the formula for
+ Find the exact time that there is
+ Exercise Answer +
+Since the water level rises at a constant rate of
At
Yes: as time increases, the volume strictly increases (more water is added continuously), so the function
Substituting
Solving
At
+ Recall that in
+
+ What familiar type of function is
+ Determine an algebraic formula for
+ What is the meaning of the statement
+ Determine the average rate of change of
+ Determine the average rate of change of
- An apartment manager keeps careful record of how the rent charged per unit corresponds to the number of occupied units in a large complex. The collected data is shown in
-
- Why is it reasonable to say that the number of occupied apartments is a linear function of rent? -
-
- Let
- Determine a formula for
- If the rent were to be increased to $1000, how many occupied apartments should the - apartment manager expect? How much total revenue would the manager collect in a given month when rent is set at $1000? -
-- Why do you think the apartment manager is interested in the data that has been collected? -
-- Exercise Answer -
-Each
Slope
At
The manager wants to find the rent that maximizes total revenue,
- Alicia and Dexter are each walking on a straight path. For a particular
The velocity functions
-
- Determine formulas for both
- What is the value and meaning of the slope of
- What is the value and meaning of the average rate of change of
- Is there ever a time when Alicia and Damon are walking at the same velocity? If yes, determine both the time and velocity; if not, explain why. -
-- Is is possible to determine if there is ever a time when Alicia and Damon are located at the same place on the path? If yes, determine the time and location; if not, explain why not enough information is provided. -
-- Exercise Answer -
-Read the formulas for
The slope of
Set
The velocity functions do not give us location information (we would need initial positions), so it is generally not possible to determine when/if they are at the same location.
- An inverted conical tank with depth
The inverted conical tank.
--
- How much water is in the tank at
- Explain why volume,
- Determine a formula for
- At what exact time will the tank be empty? -
-
- What is a reasonable domain to use for the model
- Exercise Answer -
-The full cone has volume
The volume decreases at a constant rate of
Setting
Domain:
+ An apartment manager keeps careful record of how the rent charged per unit corresponds to the number of occupied units in a large complex. The collected data is shown in
+
+ Why is it reasonable to say that the number of occupied apartments is a linear function of rent? +
+
+ Let
+ Determine a formula for
+ If the rent were to be increased to $1000, how many occupied apartments should the + apartment manager expect? How much total revenue would the manager collect in a given month when rent is set at $1000? +
++ Why do you think the apartment manager is interested in the data that has been collected? +
++ Exercise Answer +
+Each
Slope
At
The manager wants to find the rent that maximizes total revenue,
+ Alicia and Dexter are each walking on a straight path. For a particular
The velocity functions
+
+ Determine formulas for both
+ What is the value and meaning of the slope of
+ What is the value and meaning of the average rate of change of
+ Is there ever a time when Alicia and Damon are walking at the same velocity? If yes, determine both the time and velocity; if not, explain why. +
++ Is is possible to determine if there is ever a time when Alicia and Damon are located at the same place on the path? If yes, determine the time and location; if not, explain why not enough information is provided. +
++ Exercise Answer +
+Read the formulas for
The slope of
Set
The velocity functions do not give us location information (we would need initial positions), so it is generally not possible to determine when/if they are at the same location.
+ An inverted conical tank with depth
The inverted conical tank.
++
+ How much water is in the tank at
+ Explain why volume,
+ Determine a formula for
+ At what exact time will the tank be empty? +
+
+ What is a reasonable domain to use for the model
+ Exercise Answer +
+The full cone has volume
The volume decreases at a constant rate of
Setting
Domain:
- Two quadratic functions,
Two quadratic functions,
-
- How does the information provided enable you to find a formula for
- How does the information provided enable you to find a formula for
- Consider an additional quadratic function
- Does the graph of
- Exercise Answer -
-For
For
Set
Set
- Consider the quadratic function
-
- Determine the exact location of the vertex of
- Does
- Complete the following tables of function values and average rates of change of
- What pattern(s) do you observe in
- Exercise Answer -
-Vertex at
The minimum value is
Function values:
The function values are symmetric about
- A water balloon is tossed vertically from a window on the fourth floor of a dormitory from an initial height of
-
- What is the balloon's exact height at
- What is the exact maximum height the balloon reaches at
- What exact time did the balloon land? -
-- At what initial velocity was the balloon launched? -
-- Exercise Answer -
-The vertex occurs at
At the vertex, the initial velocity is
Set
The initial velocity is
+ Two quadratic functions,
Two quadratic functions,
+
+ How does the information provided enable you to find a formula for
+ How does the information provided enable you to find a formula for
+ Consider an additional quadratic function
+ Does the graph of
+ Exercise Answer +
+For
For
Set
Set
+ Consider the quadratic function
+
+ Determine the exact location of the vertex of
+ Does
+ Complete the following tables of function values and average rates of change of
+ What pattern(s) do you observe in
+ Exercise Answer +
+Vertex at
The minimum value is
Function values:
The function values are symmetric about
+ A water balloon is tossed vertically from a window on the fourth floor of a dormitory from an initial height of
+
+ What is the balloon's exact height at
+ What is the exact maximum height the balloon reaches at
+ What exact time did the balloon land? +
++ At what initial velocity was the balloon launched? +
++ Exercise Answer +
+The vertex occurs at
At the vertex, the initial velocity is
Set
The initial velocity is
- Suppose we have an unusual tank whose base is a perfect sphere with radius chimney
that is a circular cylinder of radius
A spherical tank with a cylindrical chimney.
-
- Let
-
- It is possible to use calculus to show that the total volume this tank can hold is
- On the blank axes provided below, sketch (by hand) possible graphs of how
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- For each graph, label any ordered pairs on the graph that you know for certain, and write at least one sentence that explains why your graphs have the shape they do. -
-- How would your graph(s) change (if at all) if the chimney was shaped like an inverted cone instead of a cylinder? Explain and discuss. -
-- Exercise Answer -
-At a fill rate of
The graph of
If the chimney were an inverted cone, its cross-section would shrink as it fills, so the height would increase more quickly in the chimney. The
- Suppose we have a tank that is a perfect sphere with radius
- Let
-
- How long does it take the tank to fill? What will the values of
- On the blank axes provided below, sketch (by hand) possible graphs of how
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- For each graph, label any ordered pairs on the graph that you know for certain, and write at least one sentence that explains why your graphs have the shape they do. -
-
- How do your responses change if the tank stays the same but instead the tank is initially full and the tank drains in such a way that the height of the water is always decreasing at a constant rate of
- Exercise Answer -
-At a constant rate of
Since the height rises linearly,
For the draining scenario:
- The relationship between the position, marker zero
on the road.
-
- Write several sentences that explain the how the car is being driven and how you make these conclusions from the graph. -
-
- How far did the car travel between
- Does the car ever travel in reverse? Why or why not? If not, how would the graph have to look to indicate such motion? -
-
- On the blank axes in
A graph of the relationship between a car's position
A graph of the relationship between a car's position
- Exercise Answer -
-Describe the car based on the graph: on intervals where
From the graph,
If the position graph is always non-decreasing (never moves backward), the car never goes in reverse. A graph that decreases (negative slope) over some interval would indicate reverse motion.
For the described motion:
+ Suppose we have an unusual tank whose base is a perfect sphere with radius chimney
that is a circular cylinder of radius
A spherical tank with a cylindrical chimney.
+
+ Let
+
+ It is possible to use calculus to show that the total volume this tank can hold is
+ On the blank axes provided below, sketch (by hand) possible graphs of how
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ For each graph, label any ordered pairs on the graph that you know for certain, and write at least one sentence that explains why your graphs have the shape they do. +
++ How would your graph(s) change (if at all) if the chimney was shaped like an inverted cone instead of a cylinder? Explain and discuss. +
++ Exercise Answer +
+At a fill rate of
The graph of
If the chimney were an inverted cone, its cross-section would shrink as it fills, so the height would increase more quickly in the chimney. The
+ Suppose we have a tank that is a perfect sphere with radius
+ Let
+
+ How long does it take the tank to fill? What will the values of
+ On the blank axes provided below, sketch (by hand) possible graphs of how
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ For each graph, label any ordered pairs on the graph that you know for certain, and write at least one sentence that explains why your graphs have the shape they do. +
+
+ How do your responses change if the tank stays the same but instead the tank is initially full and the tank drains in such a way that the height of the water is always decreasing at a constant rate of
+ Exercise Answer +
+At a constant rate of
Since the height rises linearly,
For the draining scenario:
+ The relationship between the position, marker zero
on the road.
+
+ Write several sentences that explain the how the car is being driven and how you make these conclusions from the graph. +
+
+ How far did the car travel between
+ Does the car ever travel in reverse? Why or why not? If not, how would the graph have to look to indicate such motion? +
+
+ On the blank axes in
A graph of the relationship between a car's position
A graph of the relationship between a car's position
+ Exercise Answer +
+Describe the car based on the graph: on intervals where
From the graph,
If the position graph is always non-decreasing (never moves backward), the car never goes in reverse. A graph that decreases (negative slope) over some interval would indicate reverse motion.
For the described motion:
- Let
-
- Let
- Let
- Let
- Finally, let
- Exercise Answer -
-For
For
For
Conjecture:
- Consider the parent function
-
- Consider the linear function in point-slope form given by
- How can the function
- Explain why any non-vertical line of the form
- Find a formula for the transformation of
- Exercise Answer -
-The slope is
Starting from
Horizontal shift left
- We have explored the effects of adding a constant to the output of a function,
- Let
-
- Let
Axes for plotting
Axes for plotting
- Based on your work in (a), how would you describe the effect(s) of the transformation
- Now consider the function
- How do you expect the graph of
- Exercise Answer -
-With
The transformation
+ Let
+
+ Let
+ Let
+ Let
+ Finally, let
+ Exercise Answer +
+For
For
For
Conjecture:
+ Consider the parent function
+
+ Consider the linear function in point-slope form given by
+ How can the function
+ Explain why any non-vertical line of the form
+ Find a formula for the transformation of
+ Exercise Answer +
+The slope is
Starting from
Horizontal shift left
+ We have explored the effects of adding a constant to the output of a function,
+ Let
+
+ Let
Axes for plotting
Axes for plotting
+ Based on your work in (a), how would you describe the effect(s) of the transformation
+ Now consider the function
+ How do you expect the graph of
+ Exercise Answer +
+With
The transformation
- Without using a computational device, determine the exact value of each of the following quantities. -
- --
-
-
-
-
-
-
-
- Exercise Answer -
--
- We now know three different identities involving the sine and cosine functions:
-
-
-
-
-
-
-
- Exercise Answer -
--
- Yes,
- Yes,
- No,
- Yes,
- No,
- No,
+ Without using a computational device, determine the exact value of each of the following quantities. +
+ ++
+
+
+
+
+
+
+
+ Exercise Answer +
++
+ We now know three different identities involving the sine and cosine functions:
+
+
+
+
+
+
+
+ Exercise Answer +
++
+ Yes,
+ Yes,
+ No,
+ Yes,
+ No,
+ No,
- Find a possible formula for the circular function whose values are in the following table. -
- -- Hint: Plot the points first; - doing so in Desmos is ideal. -
- -- Exercise Answer -
-
- There is more than one possible correct answer. If we take the points to indicate a period of
- In 2018, on the summer solstice, June 21, Grand Rapids, MI, experiences
- Let
- Exercise Answer -
-
- Assuming the period is
- We now understand the effects of the transformation
-
- We first consider the special case where
- Given any function
- How is the graph of
- How is the graph of
- Given any function
- How are
- Exercise Answer -
--
- The graphs of
- For any function
- The graph of
- The graph of
- For any function
- The graphs
+ Find a possible formula for the circular function whose values are in the following table. +
+ ++ Hint: Plot the points first; + doing so in Desmos is ideal. +
+ ++ Exercise Answer +
+
+ There is more than one possible correct answer. If we take the points to indicate a period of
+ In 2018, on the summer solstice, June 21, Grand Rapids, MI, experiences
+ Let
+ Exercise Answer +
+
+ Assuming the period is
+ We now understand the effects of the transformation
+
+ We first consider the special case where
+ Given any function
+ How is the graph of
+ How is the graph of
+ Given any function
+ How are
+ Exercise Answer +
++
+ The graphs of
+ For any function
+ The graph of
+ The graph of
+ For any function
+ The graphs
- Consider the circle pictured in
A point traversing the circle.
-Axes for plotting
- Recall that in
-
- What is the exact horizontal coordinate of
- Complete the entries in
- By plotting the points in
- What is similar about your graph in comparison to the one in
- What will be the value of
- Exercise Answer -
--
- The point
- The graph is just a horizontal shift compared to the graph of
- When
- Two circular functions,
A plot of the circular function
A plot of the circular function
-
- Assume that the circle used to generate the circular function is centered at the point
- What are the coordinates of the location on the circle at which the point begins its traverse? Said differently, what point on the circle corresponds to
- What is the period of the function? How is this connected to the circle and to the scale on the horizontal axes on which the function is graphed? -
-
- How would the graph look if the circle's radius was
- Exercise Answer -
--
- The midline of each oscillation graph corresponds to the center
- Assuming counterclockwise motion: the circle for function
- For function
- The changes to the graph depend in part on whether the speed stays the same. If the circle's radius gets one unit larger and the speed stays the same, then the period of the graph of function
- A person goes for a ride on a ferris wheel. They enter one of the cars at the lowest possible point on the wheel from a platform
-
- How high above the ground is the center of the ferris wheel? -
-- How far does the car travel in one complete trip around the wheel? -
-
- For the circular function
- Sketch an accurate graph of
- Exercise Answer -
--
- The center of the ferris wheel is at height
- The radius is
- The circular function
+ Consider the circle pictured in
A point traversing the circle.
+Axes for plotting
+ Recall that in
+
+ What is the exact horizontal coordinate of
+ Complete the entries in
+ By plotting the points in
+ What is similar about your graph in comparison to the one in
+ What will be the value of
+ Exercise Answer +
++
+ The point
+ The graph is just a horizontal shift compared to the graph of
+ When
+ Two circular functions,
A plot of the circular function
A plot of the circular function
+
+ Assume that the circle used to generate the circular function is centered at the point
+ What are the coordinates of the location on the circle at which the point begins its traverse? Said differently, what point on the circle corresponds to
+ What is the period of the function? How is this connected to the circle and to the scale on the horizontal axes on which the function is graphed? +
+
+ How would the graph look if the circle's radius was
+ Exercise Answer +
++
+ The midline of each oscillation graph corresponds to the center
+ Assuming counterclockwise motion: the circle for function
+ For function
+ The changes to the graph depend in part on whether the speed stays the same. If the circle's radius gets one unit larger and the speed stays the same, then the period of the graph of function
+ A person goes for a ride on a ferris wheel. They enter one of the cars at the lowest possible point on the wheel from a platform
+
+ How high above the ground is the center of the ferris wheel? +
++ How far does the car travel in one complete trip around the wheel? +
+
+ For the circular function
+ Sketch an accurate graph of
+ Exercise Answer +
++
+ The center of the ferris wheel is at height
+ The radius is
+ The circular function
- Let
-
- Suppose that
- Suppose that
- Suppose that
- At what exact point(s) does the line
- Exercise Answer -
--
- Using
- With
- Going
- Substituting
- The unit circle is centered at
-
- Explain why any point
- Determine the equation of a circle centered at
- Suppose that the unit circle is magnified by a factor of
- What is the length of the arc intercepted by a central angle of
- Suppose that the line segment from
- Exercise Answer -
--
- A circle of radius
-
-
- The circle has radius 4, so the arc length is
- The diameter has length
- Consider the circle whose center is
-
- Consider the point
- Answer the same question as in (a) except with
- How far has the point
- Let
- Exercise Answer -
--
- At
- At
- One full revolution has distance equal to the circumference:
+ Let
+
+ Suppose that
+ Suppose that
+ Suppose that
+ At what exact point(s) does the line
+ Exercise Answer +
++
+ Using
+ With
+ Going
+ Substituting
+ The unit circle is centered at
+
+ Explain why any point
+ Determine the equation of a circle centered at
+ Suppose that the unit circle is magnified by a factor of
+ What is the length of the arc intercepted by a central angle of
+ Suppose that the line segment from
+ Exercise Answer +
++
+ A circle of radius
+
+
+ The circle has radius 4, so the arc length is
+ The diameter has length
+ Consider the circle whose center is
+
+ Consider the point
+ Answer the same question as in (a) except with
+ How far has the point
+ Let
+ Exercise Answer +
++
+ At
+ At
+ One full revolution has distance equal to the circumference:
- When a single investment of principal, $
- Suppose we invest $
-
- Compute
- Compute
- Compute
- Compute
- If we let the number of times that interest is compounded increase without bound, we say that the interest is compounded continuously
.
- How much of a difference does continuously compounded interest make over interest compounded quarterly in one year's time? How does your answer change over
- Exercise Answer -
--
- With
- With
- With
- With
- With continuous compounding:
- In one year, continuously compounded interest yields approximately
- In Desmos, define the function
-
- For what values of
- For which value of
- What is the long-term behavior of
- Experiment with the slider to find a value of
- Exercise Answer -
--
- When
- The average rate of change of
- When
- We need
- A can of soda is removed from a refrigerator at time
-
- What is the long-term behavior of the function
- What is the long-term behavior of the function
- What is the temperature of the refrigerator? Why? -
-
- Compute the average rate of change of
- Exercise Answer -
--
- The long-term behavior of
- The function
- The temperature of the refrigerator is
-
+ When a single investment of principal, $
+ Suppose we invest $
+
+ Compute
+ Compute
+ Compute
+ Compute
+ If we let the number of times that interest is compounded increase without bound, we say that the interest is compounded continuously
.
+ How much of a difference does continuously compounded interest make over interest compounded quarterly in one year's time? How does your answer change over
+ Exercise Answer +
++
+ With
+ With
+ With
+ With
+ With continuous compounding:
+ In one year, continuously compounded interest yields approximately
+ In Desmos, define the function
+
+ For what values of
+ For which value of
+ What is the long-term behavior of
+ Experiment with the slider to find a value of
+ Exercise Answer +
++
+ When
+ The average rate of change of
+ When
+ We need
+ A can of soda is removed from a refrigerator at time
+
+ What is the long-term behavior of the function
+ What is the long-term behavior of the function
+ What is the temperature of the refrigerator? Why? +
+
+ Compute the average rate of change of
+ Exercise Answer +
++
+ The long-term behavior of
+ The function
+ The temperature of the refrigerator is
+
- Grinnell Glacier in Glacier National Park in Montana covered about
-
- Let
- How many acres of ice were in the glacier in 1997? - In 2012? - What does the model predict for 2022? -
-- How many total acres of ice were lost from 2007 to 2012? -
-
- What was the average rate of change of
- How would you you describe the overall behavior of
- Exercise Answer -
--
- The area of Grinnell Glacier is
- In 1997 (
- According to the model, between 2007 and 2012 the glacier lost about
- The average rate of change of
- The Grinnell Glacier is retreating at a decreasing rate. -
-
- Consider the exponential function
A plot of the exponential function
-
- Determine the values of
- Determine the average rate of change of
- Find the equation of the linear function
- Which average rate of change is greater? The average rate of change of
- Exercise Answer -
--
- Taking the ratio of the two given points:
-
- A linear equation passing through
- Given that the rate of decrease of the exponential function
- A cup of hot coffee is brought outside on a cold winter morning in Winnipeg, Manitoba, where the surrounding temperature is
-
- Assume that the data in the table represents the overall trend of the behavior of
- Is it possible to determine an exact formula for
- What is the average rate of change of
- How do you think the data would appear if instead of being in a regular coffee cup, the coffee was contained in an insulated mug? -
-- Exercise Answer -
--
- The function described by the data appears exponential because there is a consistent ratio of about
- It is necessary to take the square root of the ratio between 2-minute measurements to find the 1-minute growth factor. A possible formula is
-
- An insulating mug would reduce the rate of cooling, but the temperature would still follow an exponential model. The growth factor would be less than 1 but closer to 1 than
- The amount (in milligrams) of a drug in a person's body following one dose is given by an exponential decay function. Let
-
- Find a formula for
- What is the size of the initial dose the person was given? -
-
- How much of the drug remains in the person's body
- Estimate how long it will take until there is less than
- Compute the average rate of change of
- Plot
- Exercise Answer -
--
- The value of
- The initial dose is equal to the coefficient
- Eight hours after the initial dose, the remaining amount is
- There will be less than
-
- A graph of the model is shown below. -
-
+ Grinnell Glacier in Glacier National Park in Montana covered about
+
+ Let
+ How many acres of ice were in the glacier in 1997? + In 2012? + What does the model predict for 2022? +
++ How many total acres of ice were lost from 2007 to 2012? +
+
+ What was the average rate of change of
+ How would you you describe the overall behavior of
+ Exercise Answer +
++
+ The area of Grinnell Glacier is
+ In 1997 (
+ According to the model, between 2007 and 2012 the glacier lost about
+ The average rate of change of
+ The Grinnell Glacier is retreating at a decreasing rate. +
+
+ Consider the exponential function
A plot of the exponential function
+
+ Determine the values of
+ Determine the average rate of change of
+ Find the equation of the linear function
+ Which average rate of change is greater? The average rate of change of
+ Exercise Answer +
++
+ Taking the ratio of the two given points:
+
+ A linear equation passing through
+ Given that the rate of decrease of the exponential function
+ A cup of hot coffee is brought outside on a cold winter morning in Winnipeg, Manitoba, where the surrounding temperature is
+
+ Assume that the data in the table represents the overall trend of the behavior of
+ Is it possible to determine an exact formula for
+ What is the average rate of change of
+ How do you think the data would appear if instead of being in a regular coffee cup, the coffee was contained in an insulated mug? +
++ Exercise Answer +
++
+ The function described by the data appears exponential because there is a consistent ratio of about
+ It is necessary to take the square root of the ratio between 2-minute measurements to find the 1-minute growth factor. A possible formula is
+
+ An insulating mug would reduce the rate of cooling, but the temperature would still follow an exponential model. The growth factor would be less than 1 but closer to 1 than
+ The amount (in milligrams) of a drug in a person's body following one dose is given by an exponential decay function. Let
+
+ Find a formula for
+ What is the size of the initial dose the person was given? +
+
+ How much of the drug remains in the person's body
+ Estimate how long it will take until there is less than
+ Compute the average rate of change of
+ Plot
+ Exercise Answer +
++
+ The value of
+ The initial dose is equal to the coefficient
+ Eight hours after the initial dose, the remaining amount is
+ There will be less than
+
+ A graph of the model is shown below. +
+
- For a population that is growing exponentially according to a model of the form
-
- Suppose that a certain population initially has
- A different population is observed to satisfy
- Another population is observed to have doubling time
- How is
- Exercise Answer -
--
- Since the population initially has
- Since
- If the doubling time is
- If the doubling time is
- A new car is purchased for $
-
- Determine the exact values of
- How many years will it take until the car's value is $
- Suppose that rather than having the car's value decay all the way to $
- Under the original assumptions (
- Exercise Answer -
--
- At purchase (
- We solve
- As
- With
- In
- Recall that
-
- Write the equation
- Take the equation you found in (a) and take the natural logarithm of each side. -
-
- Use rules and properties of logarithms appropriately to solve the equation from (b) for
- Recall that
- What is the value of
- Exercise Answer -
--
- The equation
- Taking the natural log of both sides of
- Dividing both sides by
- Since
- Since
+ For a population that is growing exponentially according to a model of the form
+
+ Suppose that a certain population initially has
+ A different population is observed to satisfy
+ Another population is observed to have doubling time
+ How is
+ Exercise Answer +
++
+ Since the population initially has
+ Since
+ If the doubling time is
+ If the doubling time is
+ A new car is purchased for $
+
+ Determine the exact values of
+ How many years will it take until the car's value is $
+ Suppose that rather than having the car's value decay all the way to $
+ Under the original assumptions (
+ Exercise Answer +
++
+ At purchase (
+ We solve
+ As
+ With
+ In
+ Recall that
+
+ Write the equation
+ Take the equation you found in (a) and take the natural logarithm of each side. +
+
+ Use rules and properties of logarithms appropriately to solve the equation from (b) for
+ Recall that
+ What is the value of
+ Exercise Answer +
++
+ The equation
+ Taking the natural log of both sides of
+ Dividing both sides by
+ Since
+ Since
- Recall that when a function
- Find the inverse function for each given function by solving algebraically for
-
-
-
-
-
-
-
-
- Exercise Answer -
--
- The domain of
- The domain of
- The domain of
- The domain of
- The domain of
- The domain of
- The domain of
- We've seen that any exponential function
- Let
- In Desmos, the natural logarithm function is given by
- In a new Desmos worksheet, enter
-
- Define
- Repeat (a) for the functions
- True or false: for any value of
- Compute the following values:
- Exercise Answer -
--
- In Desmos, entering
- Similarly, the values of
- True. For any
- We compute
- A can of soda is removed from a refrigerator at time
-
- Determine the exact time when the soda's temperature is
- Is there ever a time when the soda's temperature is
- For the model, its domain is the set of all positive real numbers,
- Find a formula for the inverse of the function
- Exercise Answer -
--
- We solve
- At
- Since
- Solving
+ Recall that when a function
+ Find the inverse function for each given function by solving algebraically for
+
+
+
+
+
+
+
+
+ Exercise Answer +
++
+ The domain of
+ The domain of
+ The domain of
+ The domain of
+ The domain of
+ The domain of
+ The domain of
+ We've seen that any exponential function
+ Let
+ In Desmos, the natural logarithm function is given by
+ In a new Desmos worksheet, enter
+
+ Define
+ Repeat (a) for the functions
+ True or false: for any value of
+ Compute the following values:
+ Exercise Answer +
++
+ In Desmos, entering
+ Similarly, the values of
+ True. For any
+ We compute
+ A can of soda is removed from a refrigerator at time
+
+ Determine the exact time when the soda's temperature is
+ Is there ever a time when the soda's temperature is
+ For the model, its domain is the set of all positive real numbers,
+ Find a formula for the inverse of the function
+ Exercise Answer +
++
+ We solve
+ At
+ Since
+ Solving
- A can of soda has been in a refrigerator for several days; the refrigerator has temperature
-
- What is the numerical value of the soda's initial temperature? What is the value of
- What is the numerical value of the soda's long-term temperature? What is the long-term value of
- Using your work in (a) and (b), determine the numerical values of
- Suppose it can be determined that
- Exercise Answer -
--
- The soda's initial temperature is
- The soda's long-term temperature is the room temperature,
- Using
- With
- Consider the graphs of the following four functions
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- For each function
- whether
- whether
- whether
- the range of the function in terms of
- Exercise Answer -
-
- Each function has the form
- A cup of coffee has its temperature,
- In addition, recall that we can convert between Celsius and Fahrenheit according to the equations
- Exercise Answer -
-
- Assuming a cooling law of the form
- Converting to Fahrenheit:
+ A can of soda has been in a refrigerator for several days; the refrigerator has temperature
+
+ What is the numerical value of the soda's initial temperature? What is the value of
+ What is the numerical value of the soda's long-term temperature? What is the long-term value of
+ Using your work in (a) and (b), determine the numerical values of
+ Suppose it can be determined that
+ Exercise Answer +
++
+ The soda's initial temperature is
+ The soda's long-term temperature is the room temperature,
+ Using
+ With
+ Consider the graphs of the following four functions
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ For each function
+ whether
+ whether
+ whether
+ the range of the function in terms of
+ Exercise Answer +
+
+ Each function has the form
+ A cup of coffee has its temperature,
+ In addition, recall that we can convert between Celsius and Fahrenheit according to the equations
+ Exercise Answer +
+
+ Assuming a cooling law of the form
+ Converting to Fahrenheit:
In find
, this use of
is not in reference to carrying capacity.
- A glass filled with ice and water is set on a table in a climate-controlled room with constant temperature of
-
- Make a rough sketch of how you think the temperature graph should appear. Is the temperature function always increasing? always decreasing? always concave up? always concave down? what's its long-range behavior? -
-
- By describing
- Use the given information to determine the exact values of
- Determine the exact time when the water's temperature is
- Exercise Answer -
--
- The temperature is always increasing (the ice water warms toward room temperature), concave down, and approaches
- The function
- Since
- Setting
- A popular cruise ship sets sail in the Gulf of Mexico with
- Let
-
- Recall we know that
- How many days will it take for
- Compute the average rate of change of
- Exercise Answer -
--
- Since all
- Setting
- The average rates of change are approximately
- A closed tank with an inflow and outflow contains a
- It turns out that the problem of determining the amount of salt in the tank at time
-
- How much salt is in the tank initially? -
-- In the long run, how much salt do we expect to eventually be in the tank? -
-
- At what exact time are there exactly
- Can you determine the concentration of the solution that is being delivered by the inflow to the tank? If yes, explain why and determine this value. If not, explain why that information cannot be found without additional data. -
-- Exercise Answer -
--
- At
- As
- Setting
- Yes. In the long run, the tank contains
In find
, this use of
is not in reference to carrying capacity.
+ A glass filled with ice and water is set on a table in a climate-controlled room with constant temperature of
+
+ Make a rough sketch of how you think the temperature graph should appear. Is the temperature function always increasing? always decreasing? always concave up? always concave down? what's its long-range behavior? +
+
+ By describing
+ Use the given information to determine the exact values of
+ Determine the exact time when the water's temperature is
+ Exercise Answer +
++
+ The temperature is always increasing (the ice water warms toward room temperature), concave down, and approaches
+ The function
+ Since
+ Setting
+ A popular cruise ship sets sail in the Gulf of Mexico with
+ Let
+
+ Recall we know that
+ How many days will it take for
+ Compute the average rate of change of
+ Exercise Answer +
++
+ Since all
+ Setting
+ The average rates of change are approximately
+ A closed tank with an inflow and outflow contains a
+ It turns out that the problem of determining the amount of salt in the tank at time
+
+ How much salt is in the tank initially? +
++ In the long run, how much salt do we expect to eventually be in the tank? +
+
+ At what exact time are there exactly
+ Can you determine the concentration of the solution that is being delivered by the inflow to the tank? If yes, explain why and determine this value. If not, explain why that information cannot be found without additional data. +
++ Exercise Answer +
++
+ At
+ As
+ Setting
+ Yes. In the long run, the tank contains
- We've observed that several different familiar functions grow without bound as
-
- Use a computational device to compute decimal expressions for
- For each of
- Consider the new function
- Exercise Answer -
--
-
-
-
- Consider the familiar graph of
A plot of
A plot of a related function
-
- How can we view
- Find a formula for
- Explain algebraically (using the form of
- What if a function
- Suppose that
- Exercise Answer -
--
-
-
- As
- A possible formula is
-
- Power functions can have powers that are not whole numbers. For instance, we can consider such functions as
-
-
- Compare and contrast the graphs of
- Observe that we can think of
- How do the graphs of
- Explore similar questions for the graphs of
- Exercise Answer -
--
- All three functions are positive for
-
-
-
+ We've observed that several different familiar functions grow without bound as
+
+ Use a computational device to compute decimal expressions for
+ For each of
+ Consider the new function
+ Exercise Answer +
++
+
+
+
+ Consider the familiar graph of
A plot of
A plot of a related function
+
+ How can we view
+ Find a formula for
+ Explain algebraically (using the form of
+ What if a function
+ Suppose that
+ Exercise Answer +
++
+
+
+ As
+ A possible formula is
+
+ Power functions can have powers that are not whole numbers. For instance, we can consider such functions as
+
+
+ Compare and contrast the graphs of
+ Observe that we can think of
+ How do the graphs of
+ Explore similar questions for the graphs of
+ Exercise Answer +
++
+ All three functions are positive for
+
+
+
- An open triangular trough, as pictured in
A triangular trough.
--
- What is the area of one of the equilateral triangle ends as a function of
- Recall that for an object with constant cross-sectional area, its volume is the area of one of those cross-sections times its height (or length). Hence determine a formula for the volume of the trough that depends on
- Find a formula involving
- Use the constraint that we have
- Use your work in (d) and (b) to express the volume of the trough,
- What is the domain of the function
- Exercise Answer -
--
- The area of an equilateral triangle with side length
- The volume of the trough is cross-sectional area times length:
- The trough has two equilateral triangular ends and two rectangular side panels (the open top means there is no rectangular top panel). The surface area is
-
- Setting the surface area equal to
- Substituting into the volume formula:
-
- We need
- A rectangular box is being constructed so that its base is twice as long as it is wide. In addition, the base and top of the box cost $
- Exercise Answer -
-
- Let the box have width
- Suppose that we want a cylindrical barrel to hold
-
- Draw several possible pictures of how the barrel might look. For instance, what if the radius is very small? How will the height appear in comparison? Likewise, what happens if the height is very small? -
-
- Use the fact that volume is fixed at
- Recall that the surface area of a cylinder is
- What is the domain of
- Explain why
- Exercise Answer -
--
- If the radius is very small, the cylinder must be very tall to hold
- The volume constraint
- Substituting into the surface area formula:
-
- The domain is
-
+ An open triangular trough, as pictured in
A triangular trough.
++
+ What is the area of one of the equilateral triangle ends as a function of
+ Recall that for an object with constant cross-sectional area, its volume is the area of one of those cross-sections times its height (or length). Hence determine a formula for the volume of the trough that depends on
+ Find a formula involving
+ Use the constraint that we have
+ Use your work in (d) and (b) to express the volume of the trough,
+ What is the domain of the function
+ Exercise Answer +
++
+ The area of an equilateral triangle with side length
+ The volume of the trough is cross-sectional area times length:
+ The trough has two equilateral triangular ends and two rectangular side panels (the open top means there is no rectangular top panel). The surface area is
+
+ Setting the surface area equal to
+ Substituting into the volume formula:
+
+ We need
+ A rectangular box is being constructed so that its base is twice as long as it is wide. In addition, the base and top of the box cost $
+ Exercise Answer +
+
+ Let the box have width
+ Suppose that we want a cylindrical barrel to hold
+
+ Draw several possible pictures of how the barrel might look. For instance, what if the radius is very small? How will the height appear in comparison? Likewise, what happens if the height is very small? +
+
+ Use the fact that volume is fixed at
+ Recall that the surface area of a cylinder is
+ What is the domain of
+ Explain why
+ Exercise Answer +
++
+ If the radius is very small, the cylinder must be very tall to hold
+ The volume constraint
+ Substituting into the surface area formula:
+
+ The domain is
+
- Consider the polynomial function given by
-
-
- What is the degree of
- What are the real zeros of
- Construct a carefully labeled sign chart for
- Plot the function
- Now consider the related but different polynomial
-
- Exercise Answer -
--
- The degree of
- The real zeros are
- The sign of
- The zeros span a large range (
-
- Consider the (non-polynomial) function
-
- What are the zeros of
- Construct a sign chart for
- Plot
- From the graph,
- what appears to be the value of
- Exercise Answer -
--
- Since
- The sign of
- In Desmos, the zeros at
-
- In each following question, find a formula for a polynomial with certain properties, generate a plot that demonstrates you’ve found a function with the given specifications, and write several sentences to explain your thinking. -
- --
- A quadratic function
- A polynomial
- A polynomial
- A polynomial
A polynomial function
- Exercise Answer -
--
-
-
- Since the stated multiplicities sum to
- Reading from the graph (which shows zeros at approximately
- Like we have worked to understand families of functions that involve parameters such as
-
- For example, let
-
- What is the degree of
- What is the long-term behavior of
- In terms of the constant
- Construct a carefully labeled sign chart for
- How does changing the value of
- Exercise Answer -
--
-
-
- Factor:
- Sign chart (with
- As
+ Consider the polynomial function given by
+
+
+ What is the degree of
+ What are the real zeros of
+ Construct a carefully labeled sign chart for
+ Plot the function
+ Now consider the related but different polynomial
+
+ Exercise Answer +
++
+ The degree of
+ The real zeros are
+ The sign of
+ The zeros span a large range (
+
+ Consider the (non-polynomial) function
+
+ What are the zeros of
+ Construct a sign chart for
+ Plot
+ From the graph,
+ what appears to be the value of
+ Exercise Answer +
++
+ Since
+ The sign of
+ In Desmos, the zeros at
+
+ In each following question, find a formula for a polynomial with certain properties, generate a plot that demonstrates you’ve found a function with the given specifications, and write several sentences to explain your thinking. +
+ ++
+ A quadratic function
+ A polynomial
+ A polynomial
+ A polynomial
A polynomial function
+ Exercise Answer +
++
+
+
+ Since the stated multiplicities sum to
+ Reading from the graph (which shows zeros at approximately
+ Like we have worked to understand families of functions that involve parameters such as
+
+ For example, let
+
+ What is the degree of
+ What is the long-term behavior of
+ In terms of the constant
+ Construct a carefully labeled sign chart for
+ How does changing the value of
+ Exercise Answer +
++
+
+
+ Factor:
+ Sign chart (with
+ As
- For each of the following rational functions, determine, with justification, the exact locations of all (i) horizontal asymptotes, (ii) vertical asymptotes, (iii) zeros, and (iv) holes of the function. Clearly show your work and thinking. -
- --
-
-
-
- Exercise Answer -
--
-
Horizontal asymptote:
Vertical asymptotes:
Zero:
Holes: at
-
Horizontal asymptote:
Vertical asymptotes:
Zeros:
Holes: none.
-
Horizontal asymptote:
Vertical asymptotes:
Zeros:
Hole: at
- Find a formula for a rational function that meets the stated criteria, with justification. If no such formula is possible, explain why. -
- --
- A rational function
- A rational function
- A rational function
- A rational function
A plot of the rational function
- Exercise Answer -
--
- We need
- We need: numerator degree greater than denominator degree (no horizontal asymptote); zeros at
- Zeros only at
- Reading from the graph: zeros near
- Graph each of the following rational functions and decide whether or not each function has an inverse function. If an inverse function exists, find its formula. In addition, state the domain and range of each function you consider (the original function as well as its inverse function, if the inverse function exists). -
- --
-
-
-
-
- Exercise Answer -
--
-
-
-
-
- For each of the following rational functions, identify the location of any potential hole in the graph. Then, create a table of function values for input values near where the hole should be located. Use your work to decide whether or not the graph indeed has a hole, with written justification. -
- --
-
-
-
-
- True or false: given
- Exercise Answer -
--
-
-
-
-
- False. Part (d) provides a counterexample: at
- In the questions that follow, we explore the average rate of change of power functions on the interval
-
- Explain why
- What is the domain of
- At the point where
- What can you say about the average rate of change of
- Now let
- Finally, let
- Exercise Answer -
--
-
-
- Factoring:
- As
- For
- For
+ For each of the following rational functions, determine, with justification, the exact locations of all (i) horizontal asymptotes, (ii) vertical asymptotes, (iii) zeros, and (iv) holes of the function. Clearly show your work and thinking. +
+ ++
+
+
+
+ Exercise Answer +
++
+
Horizontal asymptote:
Vertical asymptotes:
Zero:
Holes: at
+
Horizontal asymptote:
Vertical asymptotes:
Zeros:
Holes: none.
+
Horizontal asymptote:
Vertical asymptotes:
Zeros:
Hole: at
+ Find a formula for a rational function that meets the stated criteria, with justification. If no such formula is possible, explain why. +
+ ++
+ A rational function
+ A rational function
+ A rational function
+ A rational function
A plot of the rational function
+ Exercise Answer +
++
+ We need
+ We need: numerator degree greater than denominator degree (no horizontal asymptote); zeros at
+ Zeros only at
+ Reading from the graph: zeros near
+ Graph each of the following rational functions and decide whether or not each function has an inverse function. If an inverse function exists, find its formula. In addition, state the domain and range of each function you consider (the original function as well as its inverse function, if the inverse function exists). +
+ ++
+
+
+
+
+ Exercise Answer +
++
+
+
+
+
+ For each of the following rational functions, identify the location of any potential hole in the graph. Then, create a table of function values for input values near where the hole should be located. Use your work to decide whether or not the graph indeed has a hole, with written justification. +
+ ++
+
+
+
+
+ True or false: given
+ Exercise Answer +
++
+
+
+
+
+ False. Part (d) provides a counterexample: at
+ In the questions that follow, we explore the average rate of change of power functions on the interval
+
+ Explain why
+ What is the domain of
+ At the point where
+ What can you say about the average rate of change of
+ Now let
+ Finally, let
+ Exercise Answer +
++
+
+
+ Factoring:
+ As
+ For
+ For
- For each rational function below, determine the function's domain as well as any horizontal asymptotes. -
- --
-
-
-
-
- Exercise Answer -
--
-
-
-
-
- A rectangular box is being constructed so that its base is
-
- Draw a labeled picture of the box with
- Determine a formula involving
- Use your work from (b) along with the given information about cost to determine a formula for the total cost,
- Use the volume constraint given in the problem to write an equation that relates
- Combine your work in (c) and (d) to write the cost,
- What is the domain of the cost function? How does a graph of the cost function appear? What does this suggest about the ideal box for the given constraints? -
-- Exercise Answer -
--
- The box has width
- The surface area is: base and top each
- Cost:
- Volume constraint:
- Substituting:
-
- The domain is
- A cylindrical can is being constructed so that its volume is side
of the can costs $
- You may find it helpful to ask yourself a sequence of questions like those stated in
- Exercise Answer -
-
- With radius
+ For each rational function below, determine the function's domain as well as any horizontal asymptotes. +
+ ++
+
+
+
+
+ Exercise Answer +
++
+
+
+
+
+ A rectangular box is being constructed so that its base is
+
+ Draw a labeled picture of the box with
+ Determine a formula involving
+ Use your work from (b) along with the given information about cost to determine a formula for the total cost,
+ Use the volume constraint given in the problem to write an equation that relates
+ Combine your work in (c) and (d) to write the cost,
+ What is the domain of the cost function? How does a graph of the cost function appear? What does this suggest about the ideal box for the given constraints? +
++ Exercise Answer +
++
+ The box has width
+ The surface area is: base and top each
+ Cost:
+ Volume constraint:
+ Substituting:
+
+ The domain is
+ A cylindrical can is being constructed so that its volume is side
of the can costs $
+ You may find it helpful to ask yourself a sequence of questions like those stated in
+ Exercise Answer +
+
+ With radius
- At an airshow, a pilot is flying low over a runway while maintaining a constant altitude of
-
- What is the angle of depression from the plane to the building when the plane is
- What is the angle of depression when the plane is
- How far did the plane travel during the time between the two different observations? -
-- What is the plane's velocity (in miles per hour)? -
-- Exercise Answer -
--
- The plane is at altitude
- When the slant distance is
- The horizontal distance at
- Traveling
- On a calm day, a photographer is filming a hot air balloon. When the balloon launches, the photographer is stationed
-
- When the balloon is
- When the balloon is
- Let
- Determine
- Exercise Answer -
--
- When the balloon is
- When the balloon is
- The angle of elevation as a function of height is
- The average rate of change on
- Consider a right triangle where the two legs measure
-
- What is the exact value of
- What is the exact value of
- What is the exact value of
- What is the exact radian measure of
- What is the exact radian measure of
- True or false: for any two angles
- Exercise Answer -
--
- The hypotenuse has length
-
-
-
-
- True. If
+ At an airshow, a pilot is flying low over a runway while maintaining a constant altitude of
+
+ What is the angle of depression from the plane to the building when the plane is
+ What is the angle of depression when the plane is
+ How far did the plane travel during the time between the two different observations? +
++ What is the plane's velocity (in miles per hour)? +
++ Exercise Answer +
++
+ The plane is at altitude
+ When the slant distance is
+ The horizontal distance at
+ Traveling
+ On a calm day, a photographer is filming a hot air balloon. When the balloon launches, the photographer is stationed
+
+ When the balloon is
+ When the balloon is
+ Let
+ Determine
+ Exercise Answer +
++
+ When the balloon is
+ When the balloon is
+ The angle of elevation as a function of height is
+ The average rate of change on
+ Consider a right triangle where the two legs measure
+
+ What is the exact value of
+ What is the exact value of
+ What is the exact value of
+ What is the exact radian measure of
+ What is the exact radian measure of
+ True or false: for any two angles
+ Exercise Answer +
++
+ The hypotenuse has length
+
+
+
+
+ True. If
- Use the special points on the unit circle (see, for instance,
-
-
-
-
-
-
-
-
-
-
-
- Exercise Answer -
--
- For each of the following claims, determine whether the statement is true or false. If true, write one sentence to justify your reasoning. If false, give an example of a value that shows the claim fails. -
- --
- For any
- For any real number
- For any real number
- For any
- For any real number
- For any real number
- Exercise Answer -
--
- True. Sine is the inverse function of arcsine, and therefore
- False. For example,
- False. For example,
- True. Cosine is the inverse function of arccosine, and therefore
- True. Tangent is the inverse function of arctangent, and therefore
- False. For example,
- Let's consider the composite function
-
- What is the domain of
- Since the arcsine function produces an angle, let's say that
The right triangle that corresponds to the angle
The right triangle that corresponds to the angle
- What is the value of
- How about the function
- Exercise Answer -
--
- The domain of
- With hypotenuse
- We have
- Let
+ Use the special points on the unit circle (see, for instance,
+
+
+
+
+
+
+
+
+
+
+
+ Exercise Answer +
++
+ For each of the following claims, determine whether the statement is true or false. If true, write one sentence to justify your reasoning. If false, give an example of a value that shows the claim fails. +
+ ++
+ For any
+ For any real number
+ For any real number
+ For any
+ For any real number
+ For any real number
+ Exercise Answer +
++
+ True. Sine is the inverse function of arcsine, and therefore
+ False. For example,
+ False. For example,
+ True. Cosine is the inverse function of arccosine, and therefore
+ True. Tangent is the inverse function of arctangent, and therefore
+ False. For example,
+ Let's consider the composite function
+
+ What is the domain of
+ Since the arcsine function produces an angle, let's say that
The right triangle that corresponds to the angle
The right triangle that corresponds to the angle
+ What is the value of
+ How about the function
+ Exercise Answer +
++
+ The domain of
+ With hypotenuse
+ We have
+ Let
- Let
- How do your answers change if
- Exercise Answer -
-
- With
- If
- For each of the following transformations of standard trigonometric functions, use your understanding of transformations to determine the domain, range, asymptotes, and period of the function, with careful justification. Then, check your results using Desmos or another graphing utility. -
- --
-
-
-
-
- Exercise Answer -
--
-
-
-
-
- In a right triangle with hypotenuse 1 and vertical leg
-
-
-
-
-
-
-
- Exercise Answer -
-
- In the right triangle, the horizontal leg has length
+ Let
+ How do your answers change if
+ Exercise Answer +
+
+ With
+ If
+ For each of the following transformations of standard trigonometric functions, use your understanding of transformations to determine the domain, range, asymptotes, and period of the function, with careful justification. Then, check your results using Desmos or another graphing utility. +
+ ++
+
+
+
+
+ Exercise Answer +
++
+
+
+
+
+ In a right triangle with hypotenuse 1 and vertical leg
+
+
+
+
+
+
+
+ Exercise Answer +
+
+ In the right triangle, the horizontal leg has length
- A person standing
- Exercise Answer -
-
- Let the angle of elevation be
- A person watching a rocket launch uses a laser range-finder to measure the distance from themselves to the rocket. The range-finder also reports the angle at which the finder is being elevated from horizontal. At a certain instant, the range-finder reports that it is elevated at an angle of
- Exercise Answer -
-
- With the range-finder elevated at
- A trough is constructed by bending a
A cross-section of the trough.
-- The volume of the trough is the area of a cross-section times the length of the trough. -
-- Exercise Answer -
-
- Each side panel is a
+ A person standing
+ Exercise Answer +
+
+ Let the angle of elevation be
+ A person watching a rocket launch uses a laser range-finder to measure the distance from themselves to the rocket. The range-finder also reports the angle at which the finder is being elevated from horizontal. At a certain instant, the range-finder reports that it is elevated at an angle of
+ Exercise Answer +
+
+ With the range-finder elevated at
+ A trough is constructed by bending a
A cross-section of the trough.
++ The volume of the trough is the area of a cross-section times the length of the trough. +
++ Exercise Answer +
+
+ Each side panel is a
- A wheelchair ramp is to be built so that the angle it forms with level ground is
- Exercise Answer -
-
- The ramp makes a
- A person is flying a kite and at the end of a fixed length of string. Assume there is no slack in the string. -
- -
- At a certain moment, the kite is
-
- How far is it from the person flying the kite to another person who is standing directly beneath the kite? -
-- How much string is out between the person flying the kite and the kite itself? -
-
- With the same amount of string out, the angle of elevation increases to
- Exercise Answer -
--
- With the kite at
- The string length is
- With the same string length and elevation angle
- An airplane is flying at a constant speed along a straight path above a straight road at a constant elevation of
- How far did the plane travel during the two seconds between the two angle measurements? How fast was the plane flying? -
-- Exercise Answer -
-
- At angle
+ A wheelchair ramp is to be built so that the angle it forms with level ground is
+ Exercise Answer +
+
+ The ramp makes a
+ A person is flying a kite and at the end of a fixed length of string. Assume there is no slack in the string. +
+ +
+ At a certain moment, the kite is
+
+ How far is it from the person flying the kite to another person who is standing directly beneath the kite? +
++ How much string is out between the person flying the kite and the kite itself? +
+
+ With the same amount of string out, the angle of elevation increases to
+ Exercise Answer +
++
+ With the kite at
+ The string length is
+ With the same string length and elevation angle
+ An airplane is flying at a constant speed along a straight path above a straight road at a constant elevation of
+ How far did the plane travel during the two seconds between the two angle measurements? How fast was the plane flying? +
++ Exercise Answer +
+
+ At angle
- This text began as my sabbatical project in the fall semester of 2018, - during which I wrote most of the material. - For the sabbatical leave, I express my deep gratitude to Grand Valley State University for its support of the project, - as well as to my colleagues in the Department of Mathematics and the College of Liberal Arts and Sciences for their endorsement of the project. - - -
- -
- The beautiful full-color .eps graphics, as well as the occasional interactive JavaScript graphics, use David Austin's Python library that employs Bill Casselman's
- Users of the text contribute important insight: they find errors, suggest improvements, and offer feedback and impressions. I'm grateful for all of it. As you use the text, I hope you'll contact me to share anything you think could make the book better. -
- -- The following contributing editors have offered feedback that includes information about typographical errors or suggestions to improve the exposition. -
- -
- This text is designed for college students who aspire to take calculus and who either need to take a course to prepare them for calculus or want to do some additional self-study. Many of the core topics of the course will be familiar to students who have completed high school. At the same time, we take a perspective on every topic that emphasizes how it is important in calculus. This text is written in the spirit of
- Many courses at the high school and college level with titles such as college algebra
, precalculus
, and trigonometry
serve other disciplines and courses other than calculus. As such, these prerequisite classes frequently contain wide-ranging material that, while mathematically interesting and important, isn't necessary for calculus. Perhaps because of these additional topics, certain ideas that are essential in calculus are under-emphasized or ignored. In
-
- Functions as processes. The mathematical concept of function is sophisticated. Understanding how a function is a special mathematical process that converts a collection of inputs to a collection of outputs is crucial for success in calculus, as calculus is the study of how functions change. -
-- Average rate of change. The central idea in differential calculus is the instantaneous rate of change of a function, which measures how fast a function's output changes with respect to changes in the input at a particular location. Because instantaneous rate of change is defined in terms of average rate of change, it's essential that students are comfortable and familiar with the idea, meaning, and applications of average rate of change. -
-- Library of basic functions. The vast majority of functions in calculus come from an algebraic combination of a collection of familiar basic functions that include power, circular, exponential, and logarithmic functions. By developing understanding of a relatively small family of basic functions and using these along with transformations to consider larger collections of functions, we work to make the central objects of calculus more intuitive and accessible. -
-- Families of functions that model important phenomena. Mathematics is the language of science, and it's remarkable how effective mathematics is at representing observable physical phenomena. From quadratic functions that model how an object falls under the influence of gravity, to shifted exponential functions that model how coffee cools, to sinusoidal functions that model how a spring-mass system oscillates, familiar basic functions find many important applications in the world around us. We regularly use these physical situations to help us see the importance of functions and to understand how families of functions that depend on different parameters are needed to represent these situations. -
-- The sine and cosine are circular functions. Many students are first introduced to the sine and cosine functions through right triangles. While this perspective is important, it is more important in calculus and other advanced courses to understand how the sine and cosine functions arise from a point traversing a circle. We take this circular function perspective early and first, and do so in order to develop deep understanding of how the familiar sine and cosine waves are generated. -
-- Inverses of functions. When a function has an inverse function, the inverse function affords us the opportunity to view an idea from a new perspective. Inverses also play a crucial role in solving algebraic equations and in determining unknown parameters in models. We emphasize the perspective that an inverse function is a process that reverses the process of the original function, as well as important basic functions that arise as inverses of other functions, especially logarithms and inverse trigonometric functions. -
-
- Exact values versus approximate ones. The ability to represent numbers exactly is a powerful tool in mathematics. We regularly and consistently distinguish between a number's exact value, such as
- Finding function formulas in applied settings. In applied settings with unknown variables, it's especially useful to be able to represent relationships among variables, since such relationships often lead to functions whose behavior we can study. We work throughout Active Prelude to Calculus to ready students for problems in calculus that ask them to develop function formulas by observing relationships. -
-- Long-term trends, unbounded behavior, and limits. By working to study functions as objects themselves, we often focus on trends and overall behavior. In addition to introducing the ideas of a function being increasing or decreasing, or concave up or concave down, we also focus on using algebraic approaces to comprehend function behavior where the input and/or output increase without bound. In anticipation of calculus, we use limit notation and work to understand how this shorthand summarizes key features of functions. -
-- Instructors and students alike will find several consistent features in the presentation, - including: -
- At the start of each section,
- we list 2
- Each section of the text begins with a short introduction, - followed by a preview activity. - This brief reading and preview activity are designed to foreshadow the upcoming ideas in the remainder of the section; - both the reading and preview activity are intended to be accessible to students - in advance of class, - and indeed to be completed by students before the particular section is to be considered - in class. -
-- A typical section in the text has at least three activities. - These are designed to engage students in an inquiry-based style that encourages them to construct solutions to key examples on their own, - working in small groups or individually. -
-
- There are dozens of college algebra and trignometry texts with (collectively) tens of thousands of exercises.
- Rather than repeat standard and routine exercises in this text,
- we recommend the use of
-
- As much as possible,
- we strive to demonstrate key fundamental ideas visually,
- and to encourage students to do the same.
- Throughout the text, we use full-color
- Many of the ideas of how functions behave are best understood dynamically; - applets offer an often ideal format for investigations and demonstrations. - Desmos provides a free and easy-to-use online graphing utility that we occasionally link to and often direct students to use. Thanks to David Austin, there are also select interactive javascript figures within the text itself. -
-- Each section concludes with a summary of the key ideas encountered in the preceding section; - this summary normally reflects responses to the motivating questions that began the section. -
-- This book is different. -
- -
- The text is available in three different formats: HTML, PDF, and print, each of which is available via links on the landing page at
- This book is intended to be read sequentially and engaged with, much more than to be used as a lookup reference. For example, each section begins with a short introduction and a Preview Activity; you should read the short introduction and complete the Preview Activity prior to class. Your instructor may require you to do this. Most Preview Activities can be completed in 15-20 minutes and are intended to be accessible based on the understanding you have from preceding sections. -
- -
- As you use the book, think of it as a workbook, not a worked-book. There is a great deal of scholarship that shows people learn better when they interactively engage and struggle with ideas themselves, rather than passively watch others. Thus, instead of reading worked examples or watching an instructor complete examples, you will engage with Activities that prompt you to grapple with concepts and develop deep understanding. You should expect to spend time in class working with peers on Activities and getting feedback from them and from your instructor. You can purchase a separate Activities Workbook download PDF
in the student workbook section) that has only the activities along with room to record your work. Your goal should be to do all of the activities in the relevant sections of the text and keep a careful record of your work.
-
- Each section concludes with a Summary. Reading the Summary after you have read the section and worked the Activities is a good way to find a short list of key ideas that are most essential to take from the section. A good study habit is to write similar summaries in your own words. -
- -
- At the end of each section, you'll find two types of Exercises. First, there are several anonymous
- The best way to be successful in mathematics generally and calculus specifically is to strive to make sense of the main ideas. We make sense of ideas by asking questions, interacting with others, attempting to solve problems, making mistakes, revising attempts, and writing and speaking about our understanding. This text has been designed to help you make sense of key ideas that are needed in calculus and to help you be well-prepared for success in calculus; we wish you the very best as you undertake the large and challenging task of doing so. -
- -
- This book is different. Before you read further, first read Students! Read this!
Our Goals
- Among the three formats (HTML, PDF, print), the HTML is optimal for display in class if you have a suitable projector. The HTML is also best for navigation, as links to internal and external references are much more obvious. We recommend saving a downloaded version of the PDF format as a backup in the event you don't have internet access. It's a good idea for each student to have a printed version of the Activities Workbook, which can be purchased download PDF
in the student workbook section) that has only the activities along with room to work; many instructors use the PDF to have coursepacks printed for students to purchase from their local bookstore.
-
- The text is written so that, on average, one section corresponds to two hours of class meeting time. A typical instructional sequence when starting a new section might look like the following: -
- Students complete a Preview Activity in advance of class. Class begins with a short debrief among peers followed by all class discussion. (5-10 minutes) -
-- Brief lecture and discussion to build on the preview activity and set the stage for the next activity. (5-10 minutes) -
-- Students engage with peers to work on and discuss the first activity in the section. (15-20 minutes) -
-- Brief discussion and possibly lecture to reach closure on the preceding activity, followed by transition to new ideas. (Varies, but 5-15 minutes) -
-- Possibly begin next activity. -
-- We recommend that instructors use appropriate incentives to encourage students to complete Preview Activities prior to class. Having these be part of completion-based assignments that count 5% of the semester grade usually results in the vast majority of students completing the vast majority of the previews. If you'd like to see a sample syllabus for how to organize a course and weight various assignments, you can request one via email to the author. -
- -
- Note that the
- The
- Thank you for considering
+ This text began as my sabbatical project in the fall semester of 2018, + during which I wrote most of the material. + For the sabbatical leave, I express my deep gratitude to Grand Valley State University for its support of the project, + as well as to my colleagues in the Department of Mathematics and the College of Liberal Arts and Sciences for their endorsement of the project. + + +
+ +
+ The beautiful full-color .eps graphics, as well as the occasional interactive JavaScript graphics, use David Austin's Python library that employs Bill Casselman's
+ Users of the text contribute important insight: they find errors, suggest improvements, and offer feedback and impressions. I'm grateful for all of it. As you use the text, I hope you'll contact me to share anything you think could make the book better. +
+ ++ The following contributing editors have offered feedback that includes information about typographical errors or suggestions to improve the exposition. +
+ +
+ This text is designed for college students who aspire to take calculus and who either need to take a course to prepare them for calculus or want to do some additional self-study. Many of the core topics of the course will be familiar to students who have completed high school. At the same time, we take a perspective on every topic that emphasizes how it is important in calculus. This text is written in the spirit of
+ Many courses at the high school and college level with titles such as college algebra
, precalculus
, and trigonometry
serve other disciplines and courses other than calculus. As such, these prerequisite classes frequently contain wide-ranging material that, while mathematically interesting and important, isn't necessary for calculus. Perhaps because of these additional topics, certain ideas that are essential in calculus are under-emphasized or ignored. In
+
+ Functions as processes. The mathematical concept of function is sophisticated. Understanding how a function is a special mathematical process that converts a collection of inputs to a collection of outputs is crucial for success in calculus, as calculus is the study of how functions change. +
++ Average rate of change. The central idea in differential calculus is the instantaneous rate of change of a function, which measures how fast a function's output changes with respect to changes in the input at a particular location. Because instantaneous rate of change is defined in terms of average rate of change, it's essential that students are comfortable and familiar with the idea, meaning, and applications of average rate of change. +
++ Library of basic functions. The vast majority of functions in calculus come from an algebraic combination of a collection of familiar basic functions that include power, circular, exponential, and logarithmic functions. By developing understanding of a relatively small family of basic functions and using these along with transformations to consider larger collections of functions, we work to make the central objects of calculus more intuitive and accessible. +
++ Families of functions that model important phenomena. Mathematics is the language of science, and it's remarkable how effective mathematics is at representing observable physical phenomena. From quadratic functions that model how an object falls under the influence of gravity, to shifted exponential functions that model how coffee cools, to sinusoidal functions that model how a spring-mass system oscillates, familiar basic functions find many important applications in the world around us. We regularly use these physical situations to help us see the importance of functions and to understand how families of functions that depend on different parameters are needed to represent these situations. +
++ The sine and cosine are circular functions. Many students are first introduced to the sine and cosine functions through right triangles. While this perspective is important, it is more important in calculus and other advanced courses to understand how the sine and cosine functions arise from a point traversing a circle. We take this circular function perspective early and first, and do so in order to develop deep understanding of how the familiar sine and cosine waves are generated. +
++ Inverses of functions. When a function has an inverse function, the inverse function affords us the opportunity to view an idea from a new perspective. Inverses also play a crucial role in solving algebraic equations and in determining unknown parameters in models. We emphasize the perspective that an inverse function is a process that reverses the process of the original function, as well as important basic functions that arise as inverses of other functions, especially logarithms and inverse trigonometric functions. +
+
+ Exact values versus approximate ones. The ability to represent numbers exactly is a powerful tool in mathematics. We regularly and consistently distinguish between a number's exact value, such as
+ Finding function formulas in applied settings. In applied settings with unknown variables, it's especially useful to be able to represent relationships among variables, since such relationships often lead to functions whose behavior we can study. We work throughout Active Prelude to Calculus to ready students for problems in calculus that ask them to develop function formulas by observing relationships. +
++ Long-term trends, unbounded behavior, and limits. By working to study functions as objects themselves, we often focus on trends and overall behavior. In addition to introducing the ideas of a function being increasing or decreasing, or concave up or concave down, we also focus on using algebraic approaces to comprehend function behavior where the input and/or output increase without bound. In anticipation of calculus, we use limit notation and work to understand how this shorthand summarizes key features of functions. +
++ Instructors and students alike will find several consistent features in the presentation, + including: +
+ At the start of each section,
+ we list 2
+ Each section of the text begins with a short introduction, + followed by a preview activity. + This brief reading and preview activity are designed to foreshadow the upcoming ideas in the remainder of the section; + both the reading and preview activity are intended to be accessible to students + in advance of class, + and indeed to be completed by students before the particular section is to be considered + in class. +
++ A typical section in the text has at least three activities. + These are designed to engage students in an inquiry-based style that encourages them to construct solutions to key examples on their own, + working in small groups or individually. +
+
+ There are dozens of college algebra and trignometry texts with (collectively) tens of thousands of exercises.
+ Rather than repeat standard and routine exercises in this text,
+ we recommend the use of
+
+ As much as possible,
+ we strive to demonstrate key fundamental ideas visually,
+ and to encourage students to do the same.
+ Throughout the text, we use full-color
+ Many of the ideas of how functions behave are best understood dynamically; + applets offer an often ideal format for investigations and demonstrations. + Desmos provides a free and easy-to-use online graphing utility that we occasionally link to and often direct students to use. Thanks to David Austin, there are also select interactive javascript figures within the text itself. +
++ Each section concludes with a summary of the key ideas encountered in the preceding section; + this summary normally reflects responses to the motivating questions that began the section. +
++ This book is different. +
+ +
+ The text is available in three different formats: HTML, PDF, and print, each of which is available via links on the landing page at
+ This book is intended to be read sequentially and engaged with, much more than to be used as a lookup reference. For example, each section begins with a short introduction and a Preview Activity; you should read the short introduction and complete the Preview Activity prior to class. Your instructor may require you to do this. Most Preview Activities can be completed in 15-20 minutes and are intended to be accessible based on the understanding you have from preceding sections. +
+ +
+ As you use the book, think of it as a workbook, not a worked-book. There is a great deal of scholarship that shows people learn better when they interactively engage and struggle with ideas themselves, rather than passively watch others. Thus, instead of reading worked examples or watching an instructor complete examples, you will engage with Activities that prompt you to grapple with concepts and develop deep understanding. You should expect to spend time in class working with peers on Activities and getting feedback from them and from your instructor. You can purchase a separate Activities Workbook download PDF
in the student workbook section) that has only the activities along with room to record your work. Your goal should be to do all of the activities in the relevant sections of the text and keep a careful record of your work.
+
+ Each section concludes with a Summary. Reading the Summary after you have read the section and worked the Activities is a good way to find a short list of key ideas that are most essential to take from the section. A good study habit is to write similar summaries in your own words. +
+ +
+ At the end of each section, you'll find two types of Exercises. First, there are several anonymous
+ The best way to be successful in mathematics generally and calculus specifically is to strive to make sense of the main ideas. We make sense of ideas by asking questions, interacting with others, attempting to solve problems, making mistakes, revising attempts, and writing and speaking about our understanding. This text has been designed to help you make sense of key ideas that are needed in calculus and to help you be well-prepared for success in calculus; we wish you the very best as you undertake the large and challenging task of doing so. +
+ +
+ This book is different. Before you read further, first read Students! Read this!
Our Goals
+ Among the three formats (HTML, PDF, print), the HTML is optimal for display in class if you have a suitable projector. The HTML is also best for navigation, as links to internal and external references are much more obvious. We recommend saving a downloaded version of the PDF format as a backup in the event you don't have internet access. It's a good idea for each student to have a printed version of the Activities Workbook, which can be purchased download PDF
in the student workbook section) that has only the activities along with room to work; many instructors use the PDF to have coursepacks printed for students to purchase from their local bookstore.
+
+ The text is written so that, on average, one section corresponds to two hours of class meeting time. A typical instructional sequence when starting a new section might look like the following: +
+ Students complete a Preview Activity in advance of class. Class begins with a short debrief among peers followed by all class discussion. (5-10 minutes) +
++ Brief lecture and discussion to build on the preview activity and set the stage for the next activity. (5-10 minutes) +
++ Students engage with peers to work on and discuss the first activity in the section. (15-20 minutes) +
++ Brief discussion and possibly lecture to reach closure on the preceding activity, followed by transition to new ideas. (Varies, but 5-15 minutes) +
++ Possibly begin next activity. +
++ We recommend that instructors use appropriate incentives to encourage students to complete Preview Activities prior to class. Having these be part of completion-based assignments that count 5% of the semester grade usually results in the vast majority of students completing the vast majority of the previews. If you'd like to see a sample syllabus for how to organize a course and weight various assignments, you can request one via email to the author. +
+ +
+ Note that the
+ The
+ Thank you for considering
- Let the height function for a ball tossed vertically be given by
- Compute the value of
- First compute
- What are the units on the quantity
- The units are feet per second. The value
- In Desmos, plot the function
-
ADD ALT TEXT TO THIS IMAGE
- Without additional context specifying when the ball is launched or lands, the
- domain and range of the model are not fully determined by the equation alone.
- The formula
- Work by hand to find the equation of the line through the points
-
- The slope is
- What is a geometric interpretation of the value
-
-
- How do your answers in the preceding questions change if we instead consider the interval
-
- Interval
- Interval
- Interval
+ Let the height function for a ball tossed vertically be given by
+ Compute the value of
+ First compute
+ What are the units on the quantity
+ The units are feet per second. The value
+ In Desmos, plot the function
+
ADD ALT TEXT TO THIS IMAGE
+ Without additional context specifying when the ball is launched or lands, the
+ domain and range of the model are not fully determined by the equation alone.
+ The formula
+ Work by hand to find the equation of the line through the points
+
+ The slope is
+ What is a geometric interpretation of the value
+
+
+ How do your answers in the preceding questions change if we instead consider the interval
+
+ Interval
+ Interval
+ Interval
- Consider the functions
ADD ALT TEXT TO THIS IMAGE
- Let
- From the table,
- Let
- From the graph,
- Are there any values of
- Yes. Setting
- Let
- From the table,
- Let
- From the graph,
- Are there any values of
- Yes:
+ Consider the functions
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+ Let
+ From the table,
+ Let
+ From the graph,
+ Are there any values of
+ Yes. Setting
+ Let
+ From the table,
+ Let
+ From the graph,
+ Are there any values of
+ Yes:
- Let
- Let
-
- Review the introductory example with
- In the introductory example, the inner function
- Let
-
- Suppose that
- One natural decomposition:
+ Let
+ Let
+
+ Review the introductory example with
+ In the introductory example, the inner function
+ Let
+
+ Suppose that
+ One natural decomposition:
- Use the equation Dolbear's Law
.
-
- If we hear snowy tree crickets chirping at a rate of
We seek
- If the outside temperature is
We seek
- Is the model valid for determining the number of chirps one should hear when the outside temperature is
The model is known to be accurate only for temperatures from
- Suppose that in the morning an observer hears
At
- Dolbear's Law is known to be accurate for temperatures from
At
+ Use the equation Dolbear's Law
.
+
+ If we hear snowy tree crickets chirping at a rate of
We seek
+ If the outside temperature is
We seek
+ Is the model valid for determining the number of chirps one should hear when the outside temperature is
The model is known to be accurate only for temperatures from
+ Suppose that in the morning an observer hears
At
+ Dolbear's Law is known to be accurate for temperatures from
At
- Recall that
- Show that it is possible to solve the equation
- Subtracting 32 from both sides:
- Note that the equation
- Find the simplest expression that you can for the composite function
-
- Find the simplest expression that you can for the composite function
-
- Why are the functions
- The function
+ Recall that
+ Show that it is possible to solve the equation
+ Subtracting 32 from both sides:
+ Note that the equation
+ Find the simplest expression that you can for the composite function
+
+ Find the simplest expression that you can for the composite function
+
+ Why are the functions
+ The function
- Let
-
- Let
- Determine
- Reading values from the table:
-
- Consider the function
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- Determine
- Reading values from the graph:
-
- What do all three examples above have in common? How do they differ? -
-
- All three functions have a constant average rate of change: the average rate of
- change is the same regardless of which interval is chosen. They differ in their
- specific rate of change (
- For the function
-
+ Let
+
+ Let
+ Determine
+ Reading values from the table:
+
+ Consider the function
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+ Determine
+ Reading values from the graph:
+
+ What do all three examples above have in common? How do they differ? +
+
+ All three functions have a constant average rate of change: the average rate of
+ change is the same regardless of which interval is chosen. They differ in their
+ specific rate of change (
+ For the function
+
- A water balloon is tossed vertically from a fifth story window. Its height,
- Execute appropriate computations to complete both of the following tables: values of the function
- Function values:
- What pattern(s) do you observe in the table of function values and in the table of average rates of change? -
-
- The function values increase from 25 to a peak of 45 at
- Explain why
- A linear function must have the same average rate of change on every interval.
- But
- What is the average velocity of the water balloon in the final second before it lands? How does this value compare to the average velocity on the time interval
- The average velocity on
+ A water balloon is tossed vertically from a fifth story window. Its height,
+ Execute appropriate computations to complete both of the following tables: values of the function
+ Function values:
+ What pattern(s) do you observe in the table of function values and in the table of average rates of change? +
+
+ The function values increase from 25 to a peak of 45 at
+ Explain why
+ A linear function must have the same average rate of change on every interval.
+ But
+ What is the average velocity of the water balloon in the final second before it lands? How does this value compare to the average velocity on the time interval
+ The average velocity on
- Suppose that a rectangular aquarium is being filled with water. The tank is
The empty aquarium.
-The aquarium, partially filled.
-- What are some different quantities that are changing in this scenario? -
-The depth of the water in the tank, the amount of water in the tank, and time are all changing.
-
- After
Since water is entering at a rate of
- How much water is in the tank and how deep is the water after
After
- How long will it take for the tank to be completely full? Why? -
-The tank holds
+ Suppose that a rectangular aquarium is being filled with water. The tank is
The empty aquarium.
+The aquarium, partially filled.
++ What are some different quantities that are changing in this scenario? +
+The depth of the water in the tank, the amount of water in the tank, and time are all changing.
+
+ After
Since water is entering at a rate of
+ How much water is in the tank and how deep is the water after
After
+ How long will it take for the tank to be completely full? Why? +
+The tank holds
- Open a new Desmos graph and define the function
- In Desmos,
- define the function
- Explore by moving the slider for
- Changing
- Next,
- define the function
- Move the slider for
- Changing
- Now define the function
- Move the slider for
- The value
- Finally, click on the icons next to
- The same three effects hold for any choice of
+ Open a new Desmos graph and define the function
+ In Desmos,
+ define the function
+ Explore by moving the slider for
+ Changing
+ Next,
+ define the function
+ Move the slider for
+ Changing
+ Now define the function
+ Move the slider for
+ The value
+ Finally, click on the icons next to
+ The same three effects hold for any choice of
- If we consider the unit circle with 16 labeled special points in Figure 2.3.1, start at
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- What is the exact value of
- The exact value of
- Complete the following table with the exact values of
- What is the exact value of
- The exact value of
- Give four different values of
-
+ If we consider the unit circle with 16 labeled special points in Figure 2.3.1, start at
ADD ALT TEXT TO THIS IMAGE
+ What is the exact value of
+ The exact value of
+ Complete the following table with the exact values of
+ What is the exact value of
+ The exact value of
+ Give four different values of
+
- Let
-
-
-
-
-
+ Let
+
+
+
+
+
- In the context of the ferris wheel pictured in Figure 2.1.1 in the text, assume that the height,
- Further, assume that the circumference of the ferris wheel is
- Recall that the circumference,
- The circumference
- How high is the cab after it has traveled
- The cab starts at the bottom, at a height of zero. At
- How much distance along the circle has the cab traversed at the moment it first reaches a height of
- The highest point of the Ferris wheel is at
- Can
- Yes. In this scenario, the height
- Can
- No. The distance
- Why do you think the curve shown at right in Figure 2.1.1 has the shape that it does? Write several sentences to explain. -
-- The curve has the shape that it does because the height of the Ferris wheel changes slowly at the bottom and at the top, where much of the distance travelled is horizontal instead of vertical. The function describing height in terms of distance is a sine function. -
-
+ In the context of the ferris wheel pictured in Figure 2.1.1 in the text, assume that the height,
+ Further, assume that the circumference of the ferris wheel is
+ Recall that the circumference,
+ The circumference
+ How high is the cab after it has traveled
+ The cab starts at the bottom, at a height of zero. At
+ How much distance along the circle has the cab traversed at the moment it first reaches a height of
+ The highest point of the Ferris wheel is at
+ Can
+ Yes. In this scenario, the height
+ Can
+ No. The distance
+ Why do you think the curve shown at right in Figure 2.1.1 has the shape that it does? Write several sentences to explain. +
++ The curve has the shape that it does because the height of the Ferris wheel changes slowly at the bottom and at the top, where much of the distance travelled is horizontal instead of vertical. The function describing height in terms of distance is a sine function. +
+
- In the following figure there are 24 equally spaced points on the unit circle. Since the circumference of the unit circle is
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- Label each of the subsequent points on the unit circle with the exact distance they lie counter-clockwise away from
- Which distance along the unit circle corresponds to
- One-quarter of a full rotation corresponds to a distance of
- One way to measure angles is connected to the arc length along a circle. For an angle whose vertex is at
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- Suppose that
- What is the radian measure that corresponds to a
-
+ In the following figure there are 24 equally spaced points on the unit circle. Since the circumference of the unit circle is
ADD ALT TEXT TO THIS IMAGE
+ Label each of the subsequent points on the unit circle with the exact distance they lie counter-clockwise away from
+ Which distance along the unit circle corresponds to
+ One-quarter of a full rotation corresponds to a distance of
+ One way to measure angles is connected to the arc length along a circle. For an angle whose vertex is at
ADD ALT TEXT TO THIS IMAGE
+ Suppose that
+ What is the radian measure that corresponds to a
+
- Open a new Desmos worksheet and define the following functions:
- By experimenting with the value of
- The value of
- Similarly, experiment to find a value of
- The value of
- For the value of
-
- For the value of
-
- Given any exponential function of the form
- Yes, it is possible to find a value of
+ Open a new Desmos worksheet and define the following functions:
+ By experimenting with the value of
+ The value of
+ Similarly, experiment to find a value of
+ The value of
+ For the value of
+
+ For the value of
+
+ Given any exponential function of the form
+ Yes, it is possible to find a value of
- Suppose that at age
- Let
- Determine
-
- Note that if a quantity depreciates
-
- Based on the patterns in your computations in (a) and (b), determine formulas for
- For the appreciating investment of $20,000:
- Use Desmos to define
ADD ALT TEXT TO THIS IMAGE
- The red curve shows the growing value of a $20,000 investment earning 8% interest per year. The blue curve shows the decreasing value of a $20,000 vehicle losing 12% of its value each year. -
-
+ Suppose that at age
+ Let
+ Determine
+
+ Note that if a quantity depreciates
+
+ Based on the patterns in your computations in (a) and (b), determine formulas for
+ For the appreciating investment of $20,000:
+ Use Desmos to define
ADD ALT TEXT TO THIS IMAGE
+ The red curve shows the growing value of a $20,000 investment earning 8% interest per year. The blue curve shows the decreasing value of a $20,000 vehicle losing 12% of its value each year. +
+
- In the following questions, we investigate how
- Write
-
- What is the simplest possible way to write
-
- Explain why each of the following three equal signs is valid in the sequence of equalities:
-
- The first equal sign holds because
- Suppose that
- Since
+ In the following questions, we investigate how
+ Write
+
+ What is the simplest possible way to write
+
+ Explain why each of the following three equal signs is valid in the sequence of equalities:
+
+ The first equal sign holds because
+ Suppose that
+ Since
- Let powers of 10
function, which is given by
- Complete the following table to generate certain values of
- Why does
- The function
- Since
- says the exact same thing as writing
. In words, where
- What are the domain and range of the function
- The domain of
+ Let powers of 10
function, which is given by
+ Complete the following table to generate certain values of
+ Why does
+ The function
+ Since
+ says the exact same thing as writing
. In words, where
+ What are the domain and range of the function
+ The domain of
- In Desmos, define
-
- Set
- When
- Follow the directions for (a) again, this time with
- The same vertical stretch and vertical shift behavior is apparent when
- Set
- When
- When
- When
+ In Desmos, define
+
+ Set
+ When
+ Follow the directions for (a) again, this time with
+ The same vertical stretch and vertical shift behavior is apparent when
+ Set
+ When
+ When
+ When
- In each of the following situations, determine the exact value of the unknown quantity that is identified. -
- -
- The temperature of a warming object in an oven is given by
- Setting
- The temperature of a cooling object in a refrigerator is modeled by
- As
- Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
-
- Multiplying both sides by
- Suppose that
- Starting from
+ In each of the following situations, determine the exact value of the unknown quantity that is identified. +
+ +
+ The temperature of a warming object in an oven is given by
+ Setting
+ The temperature of a cooling object in a refrigerator is modeled by
+ As
+ Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
+
+ Multiplying both sides by
+ Suppose that
+ Starting from
- Complete each of the following statements with an appropriate number or the symbols
- As
- As
- As
- As
- As
- As
- As
+ Complete each of the following statements with an appropriate number or the symbols
+ As
+ As
+ As
+ As
+ As
+ As
+ As
- A piece of cardboard that is
- Let
- Determine a formula for the function
After cutting
- What familiar kind of function is
- If we start with a small positive value for
The shorter side of the cardboard is
- What are the zeros of
From
+ A piece of cardboard that is
+ Let
+ Determine a formula for the function
After cutting
+ What familiar kind of function is
+ If we start with a small positive value for
The shorter side of the cardboard is
+ What are the zeros of
From
- Point your browser to the Desmos worksheet at
- What is the largest number of distinct points at which
- Recall from the definition of a polynomial function what we mean by a
- A degree 4 polynomial can cross the
- What other numbers of zeros are possible for
- A degree 4 polynomial can have
- We say that a function has a
- What is the largest number of turning points that
- A degree 4 polynomial can have at most
- What other numbers of turning points are possible for
- A degree 4 polynomial can have
- What long-range behavior is possible for
- Since the leading term is
- What happens when we plot
- When zoomed out,
+ Point your browser to the Desmos worksheet at
+ What is the largest number of distinct points at which
+ Recall from the definition of a polynomial function what we mean by a
+ A degree 4 polynomial can cross the
+ What other numbers of zeros are possible for
+ A degree 4 polynomial can have
+ We say that a function has a
+ What is the largest number of turning points that
+ A degree 4 polynomial can have at most
+ What other numbers of turning points are possible for
+ A degree 4 polynomial can have
+ What long-range behavior is possible for
+ Since the leading term is
+ What happens when we plot
+ When zoomed out,
- Consider the rational function
- Reasoning algebraically, for what values of
Factoring:
- Again reasoning algebraically, for what values of
Factoring:
- Define
Using technology to evaluate
Near
- Why does
Near
- Why does
Near
- Why does
Near
- Plot
The Desmos graph of
+ Consider the rational function
+ Reasoning algebraically, for what values of
Factoring:
+ Again reasoning algebraically, for what values of
Factoring:
+ Define
Using technology to evaluate
Near
+ Why does
Near
+ Why does
Near
+ Why does
Near
+ Plot
The Desmos graph of
- A drug company estimates that to produce a new drug,
- it will cost
- Determine a formula for a function
- The drug company needs to sell the drug at a price of more than
The total cost of producing
- What is the total cost of producing
The total cost of producing
- Our computations in (b) and (c) naturally lead us to define the average cost per gram
function,
The average cost per gram to produce
- Explain why another formula for
Dividing both terms in the numerator of
- What can you say about the long-range behavior of
As
- This activity is based on p. 457ff in Functions Modeling Change, 5th edition, by Connally et al. -
-
+ A drug company estimates that to produce a new drug,
+ it will cost
+ Determine a formula for a function
+ The drug company needs to sell the drug at a price of more than
The total cost of producing
+ What is the total cost of producing
The total cost of producing
+ Our computations in (b) and (c) naturally lead us to define the average cost per gram
function,
The average cost per gram to produce
+ Explain why another formula for
Dividing both terms in the numerator of
+ What can you say about the long-range behavior of
As
+ This activity is based on p. 457ff in Functions Modeling Change, 5th edition, by Connally et al. +
+
- Consider a right triangle that has one leg of length
- Sketch a labeled picture of the triangle. -
-- What is the exact length of the triangle's hypotenuse? -
-
- The hypotenuse has length
- What is the exact value of
- Since
- Rewrite your equation from (c) using the arcsine function in the form
- Since
- What special angle from the unit circle is
- Since
+ Consider a right triangle that has one leg of length
+ Sketch a labeled picture of the triangle. +
++ What is the exact length of the triangle's hypotenuse? +
+
+ The hypotenuse has length
+ What is the exact value of
+ Since
+ Rewrite your equation from (c) using the arcsine function in the form
+ Since
+ What special angle from the unit circle is
+ Since
- Consider the plot of the standard cosine function in the following figure along with the emphasized portion of the graph on
ADD ALT TEXT TO THIS IMAGE
- Let
- What is the domain of
The domain of
- What is the range of
The range of
- Does
Yes,
- Explain why
Since
- We know that
Since
- Determine the exact values of
+ Consider the plot of the standard cosine function in the following figure along with the emphasized portion of the graph on
ADD ALT TEXT TO THIS IMAGE
+ Let
+ What is the domain of
The domain of
+ What is the range of
The range of
+ Does
Yes,
+ Explain why
Since
+ We know that
Since
+ Determine the exact values of
- Consider a right triangle with hypotenuse of length
+ Consider a right triangle with hypotenuse of length
- For each of the following situations, sketch a right triangle that satisfies the given conditions, and then either determine the requested missing information in the triangle or explain why you don't have enough information to determine it. Assume that all angles are being considered in radian measure. -
- -
- The length of the other leg of a right triangle with hypotenuse of length
- By the Pythagorean theorem, the other leg has length
- The lengths of the two legs in a right triangle with hypotenuse of length
- In a right triangle with hypotenuse
- The length of the other leg of a right triangle with hypotenuse of length
- By the Pythagorean theorem, the other leg has length
- The lengths of the two legs in a right triangle with hypotenuse
- In a right triangle with hypotenuse
- The length of the other leg of a right triangle with hypotenuse of length
- By the Pythagorean theorem, the other leg has length
- The measures of the two angles in a right triangle with hypotenuse of length
- Since the hypotenuse is
+ For each of the following situations, sketch a right triangle that satisfies the given conditions, and then either determine the requested missing information in the triangle or explain why you don't have enough information to determine it. Assume that all angles are being considered in radian measure. +
+ +
+ The length of the other leg of a right triangle with hypotenuse of length
+ By the Pythagorean theorem, the other leg has length
+ The lengths of the two legs in a right triangle with hypotenuse of length
+ In a right triangle with hypotenuse
+ The length of the other leg of a right triangle with hypotenuse of length
+ By the Pythagorean theorem, the other leg has length
+ The lengths of the two legs in a right triangle with hypotenuse
+ In a right triangle with hypotenuse
+ The length of the other leg of a right triangle with hypotenuse of length
+ By the Pythagorean theorem, the other leg has length
+ The measures of the two angles in a right triangle with hypotenuse of length
+ Since the hypotenuse is
Using
Since
At
- Suppose that a rectangular aquarium is being filled with water. The tank is
- What are some different quantities that are changing in this scenario? -
-
- Both the
-
- After
-
- At this moment, how deep is the water? -
-
-
- How much water is in the tank and how deep is the water after
-
- After
-
- How long will it take for the tank to be completely full? -
-
-
- How much water is in a full tank?
+ Suppose that a rectangular aquarium is being filled with water. The tank is
+ What are some different quantities that are changing in this scenario? +
+
+ Both the
+
+ After
+
+ At this moment, how deep is the water? +
+
+
+ How much water is in the tank and how deep is the water after
+
+ After
+
+ How long will it take for the tank to be completely full? +
+
+
+ How much water is in a full tank?
- Let the height function for a ball tossed vertically be given by
- Compute the value of
-
-
-
- The units on
- Since the value of
- The following is a graph of -
and +
in the bottom right to zoom out or in. Clicking on the o
in the bottom right will bring it back to the start.
-
- What are the domain and range of
- The domain of
- The range of
- When modeling the motion of the ball, neither the time
-
- Below is a graph of the model of
- Calculate the equation of the line through the points
-
- Note particularly that
+ Let the height function for a ball tossed vertically be given by
+ Compute the value of
+
+
+
+ The units on
+ Since the value of
+ The following is a graph of -
and +
in the bottom right to zoom out or in. Clicking on the o
in the bottom right will bring it back to the start.
+
+ What are the domain and range of
+ The domain of
+ The range of
+ When modeling the motion of the ball, neither the time
+
+ Below is a graph of the model of
+ Calculate the equation of the line through the points
+
+ Note particularly that
- We will explore some different ways of combining functions. -
-
- First, consider the functions
- Let
-
- Let
-
- Now consider the functions
The first piece of
The second piece of
The third piece of
The first piece of
The second piece of
- Calculate exactly:
- Calculate exactly:
-
- Let
-
- Note that
- Calculate exactly:
- Calculate exactly:
-
- Let
-
- We have reproduced the graph of
Note that a fraction is undefined when the denominator is
The first piece of
The second piece of
The third piece of
The first piece of
The second piece of
+ We will explore some different ways of combining functions. +
+
+ First, consider the functions
+ Let
+
+ Let
+
+ Now consider the functions
The first piece of
The second piece of
The third piece of
The first piece of
The second piece of
+ Calculate exactly:
+ Calculate exactly:
+
+ Let
+
+ Note that
+ Calculate exactly:
+ Calculate exactly:
+
+ Let
+
+ We have reproduced the graph of
Note that a fraction is undefined when the denominator is
The first piece of
The second piece of
The third piece of
The first piece of
The second piece of
- Let
- Let
-
-
- In the introductory example with
- Let
-
-
- Suppose that
-
-
- The result of composing
+ Let
+ Let
+
+
+ In the introductory example with
+ Let
+
+
+ Suppose that
+
+
+ The result of composing
- Use the equation Dolbear's Law
.
-
- If we hear snowy tree crickets chirping at a rate of
-
- If the outside temperature is
-
- Is the model valid for determining the number of chirps one should hear when the outside temperature is
-
- Suppose that in the morning an observer hears
-
- What temperature corresponds to
- What temperature corresponds to
- Dolbear's Law is known to be accurate for temperatures from
- What is the fewest number of chirps per minute an observer could expect to hear?
- What is the greatest number of chirps per minute an observer could expect to hear?
+ Use the equation Dolbear's Law
.
+
+ If we hear snowy tree crickets chirping at a rate of
+
+ If the outside temperature is
+
+ Is the model valid for determining the number of chirps one should hear when the outside temperature is
+
+ Suppose that in the morning an observer hears
+
+ What temperature corresponds to
+ What temperature corresponds to
+ Dolbear's Law is known to be accurate for temperatures from
+ What is the fewest number of chirps per minute an observer could expect to hear?
+ What is the greatest number of chirps per minute an observer could expect to hear?
- Recall that
- Solve the equation
- The first step in solving the equation
- The second step in solving the equation
- Note that the equation
- Find the simplest expression that you can for the composite function
-
-
-
- Find the simplest expression that you can for the composite function
-
-
-
- Complete the following sentences to explain why the functions
- The function
- Then the function
- Similarly, the function
+ Recall that
+ Solve the equation
+ The first step in solving the equation
+ The second step in solving the equation
+ Note that the equation
+ Find the simplest expression that you can for the composite function
+
+
+
+ Find the simplest expression that you can for the composite function
+
+
+
+ Complete the following sentences to explain why the functions
+ The function
+ Then the function
+ Similarly, the function
- Let
-
-
-
- Let
- Determine
-
-
-
- Consider the function
- Determine
-
-
-
- Note that in each of the three examples above, the functions involved were
- For the function
-
-
-
-
- Does your answer to
+ Let
+
+
+
+ Let
+ Determine
+
+
+
+ Consider the function
+ Determine
+
+
+
+ Note that in each of the three examples above, the functions involved were
+ For the function
+
+
+
+
+ Does your answer to
- A water balloon is tossed vertically from a fifth story window. Its height,
- Complete the table of function values below. For example,
- Now use the values you computed to calculate
- Complete the following sentences to record some observations about the function
- The function
- When does the water balloon land on the ground?
-
- What is the average velocity of the water balloon in the final second before it lands?
-
- What is the average velocity of the water balloon on the interval
-
+ A water balloon is tossed vertically from a fifth story window. Its height,
+ Complete the table of function values below. For example,
+ Now use the values you computed to calculate
+ Complete the following sentences to record some observations about the function
+ The function
+ When does the water balloon land on the ground?
+
+ What is the average velocity of the water balloon in the final second before it lands?
+
+ What is the average velocity of the water balloon on the interval
+
- We are going to explore transformations of a familiar quadratic function,
- First, move the slider for
- Set the value of the slider to
- You can move it again afterwards.
-
- Which of the following observations are true for
- Next, move the slider for
- Set the value of the slider to
- You can move it again afterwards.
-
- Which of the following observations are true for
- Third, move the slider for
- Set the value of the slider to
- You can move it again afterwards.
-
- Which of the following observations are true for
- Finally, change the function entered below and explore the sliders above again for this new function. Do any of your selected choices change when the function we are comparing to has changed? You can come up with your own functions to try, but some good ones to try that will fit in the window nicely could be
-
+ We are going to explore transformations of a familiar quadratic function,
+ First, move the slider for
+ Set the value of the slider to
+ You can move it again afterwards.
+
+ Which of the following observations are true for
+ Next, move the slider for
+ Set the value of the slider to
+ You can move it again afterwards.
+
+ Which of the following observations are true for
+ Third, move the slider for
+ Set the value of the slider to
+ You can move it again afterwards.
+
+ Which of the following observations are true for
+ Finally, change the function entered below and explore the sliders above again for this new function. Do any of your selected choices change when the function we are comparing to has changed? You can come up with your own functions to try, but some good ones to try that will fit in the window nicely could be
+
- When
- Drag the point on the unit circle to the location where
- What is the exact value of
-
- What is the exact value of
-
- Complete the following table with the exact values of
- Use the patterns you observe above to answer the following questions. -
-
- What is the exact value of
-
- What is the exact value of
-
- Give four different values of
-
+ When
+ Drag the point on the unit circle to the location where
+ What is the exact value of
+
+ What is the exact value of
+
+ Complete the following table with the exact values of
+ Use the patterns you observe above to answer the following questions. +
+
+ What is the exact value of
+
+ What is the exact value of
+
+ Give four different values of
+
- Let
- Answer all of the questions below without using a graph; after answering, a graph will appear and you'll either confirm or reflect on your answers using a graph. Note that there could be more than one correct answer to some questions. -
- -
- Consider
Both
- For
- For
- When you answer the questions above correctly, some lines will appear on the graph below. Drag them to demonstrate the correct values/locations of the midline, amplitude, and period. -
-After you have the lines and locations correct, show and hide the functions above, and compare their properties to those of
- For
- Consider
Both
- For
- For
- When you answer the questions above correctly, some lines and functions will appear on the graph below. You may drag them to explore values/locations of the midline, amplitude, and period. -
-Show and hide the functions above, and compare their properties to those of
- For
- Consider
Both
- For
- For
- When you answer the questions above correctly, some lines and functions will appear on the graph below. You may drag them to explore values/locations of the midline, amplitude, and period. -
-Show and hide the functions above, and compare their properties to those of
- For
- Consider
-
- In fact,
- Based on your answers to parts a, b, and c about what transformations have been performed and your knowledge of the order of operations, in which order are the transformations applied in functions of the form
- This means that after the first transformation, the midline
- Similarly, after the first transformation, the amplitude
+ Let
+ Answer all of the questions below without using a graph; after answering, a graph will appear and you'll either confirm or reflect on your answers using a graph. Note that there could be more than one correct answer to some questions. +
+ +
+ Consider
Both
+ For
+ For
+ When you answer the questions above correctly, some lines will appear on the graph below. Drag them to demonstrate the correct values/locations of the midline, amplitude, and period. +
+After you have the lines and locations correct, show and hide the functions above, and compare their properties to those of
+ For
+ Consider
Both
+ For
+ For
+ When you answer the questions above correctly, some lines and functions will appear on the graph below. You may drag them to explore values/locations of the midline, amplitude, and period. +
+Show and hide the functions above, and compare their properties to those of
+ For
+ Consider
Both
+ For
+ For
+ When you answer the questions above correctly, some lines and functions will appear on the graph below. You may drag them to explore values/locations of the midline, amplitude, and period. +
+Show and hide the functions above, and compare their properties to those of
+ For
+ Consider
+
+ In fact,
+ Based on your answers to parts a, b, and c about what transformations have been performed and your knowledge of the order of operations, in which order are the transformations applied in functions of the form
+ This means that after the first transformation, the midline
+ Similarly, after the first transformation, the amplitude
- A simplified version of the ferris wheel scenario pictured in Figure 2.1.1 has been reproduced below. -
- -
- Assume that the height,
- Recall that the circumference,
- What is the radius of the ferris wheel?
- How high is the highest point on the ferris wheel?
- How high is the cab after it has traveled
-
- How much distance along the circle has the cab traversed at the moment it first reaches a height of
-
- Complete the following sentences. -
-
- The cab's height
- The cab's distance traveled
+ A simplified version of the ferris wheel scenario pictured in Figure 2.1.1 has been reproduced below. +
+ +
+ Assume that the height,
+ Recall that the circumference,
+ What is the radius of the ferris wheel?
+ How high is the highest point on the ferris wheel?
+ How high is the cab after it has traveled
+
+ How much distance along the circle has the cab traversed at the moment it first reaches a height of
+
+ Complete the following sentences. +
+
+ The cab's height
+ The cab's distance traveled
- In the following figure there are 24 equally spaced points on the unit circle. Since the circumference of the unit circle is
- Move the large square point to each of the points in the remainder of the top half of the circle and enter the distance traveled along the circle counterclockwise from the point
- When you have entered the correct distance for the selected point and hit enter or clicked outside the box, the distance traveled will appear on the graph near that point. -
- -
-
- Hit Check Work when all of the correct distances appear for the top half of the circle and
-
-Continuing around the circle counterclockwise after
-
- Which distance along the unit circle corresponds to
- Which distance along the unit circle corresponds to
- One way to measure angles is connected to the arc length along a circle. For an angle whose vertex is at
- In the graph on the right, drag the square point so that an angle of
- In the graph on the right, drag the square point so that an angle of
- What is the radian measure that corresponds to a
-
+ In the following figure there are 24 equally spaced points on the unit circle. Since the circumference of the unit circle is
+ Move the large square point to each of the points in the remainder of the top half of the circle and enter the distance traveled along the circle counterclockwise from the point
+ When you have entered the correct distance for the selected point and hit enter or clicked outside the box, the distance traveled will appear on the graph near that point. +
+ +
+
+ Hit Check Work when all of the correct distances appear for the top half of the circle and
+
+Continuing around the circle counterclockwise after
+
+ Which distance along the unit circle corresponds to
+ Which distance along the unit circle corresponds to
+ One way to measure angles is connected to the arc length along a circle. For an angle whose vertex is at
+ In the graph on the right, drag the square point so that an angle of
+ In the graph on the right, drag the square point so that an angle of
+ What is the radian measure that corresponds to a
+
- The functions
- Use the slider to find a value of
- When
- Use the slider to find a value of
- When
- Use the slider to find a value of
- When
- Below is another graph and slider, where now you are the one choosing the target function. -
-
- Enter a number for
- When
- When
- When
- Do you think you would be able to find a value of
+ The functions
+ Use the slider to find a value of
+ When
+ Use the slider to find a value of
+ When
+ Use the slider to find a value of
+ When
+ Below is another graph and slider, where now you are the one choosing the target function. +
+
+ Enter a number for
+ When
+ When
+ When
+ Do you think you would be able to find a value of
- Suppose that at age
- Let
- Determine
-
-
-
-
- Note that if a quantity depreciates
-
-
-
-
- Based on the patterns in your computations in parts a. and b., determine formulas for
-
-
- The graphs of
- Complete the sentence with some observations about the behavior of the two functions. -
-
- Even though both functions had the same form,
- What else do you notice and wonder? -
-
+ Suppose that at age
+ Let
+ Determine
+
+
+
+
+ Note that if a quantity depreciates
+
+
+
+
+ Based on the patterns in your computations in parts a. and b., determine formulas for
+
+
+ The graphs of
+ Complete the sentence with some observations about the behavior of the two functions. +
+
+ Even though both functions had the same form,
+ What else do you notice and wonder? +
+
- Let powers of 10
function, which is given by
- Complete the following table to generate certain values of
- We can see that the function
- Since
says the exact same thing as writing
. In words, where
-
-
+ Let powers of 10
function, which is given by
+ Complete the following table to generate certain values of
+ We can see that the function
+ Since
says the exact same thing as writing
. In words, where
+
+
- In the following questions, we investigate how
- Write
-
- Enter the simplest possible way to write each of the expressions below.
-
-
-
- Select the reason why each of the following equalities is true. -
-
-
-
-
- Putting it all together,
-
- Suppose that
- where the missing entries are:
- In conclusion,
+ In the following questions, we investigate how
+ Write
+
+ Enter the simplest possible way to write each of the expressions below.
+
+
+
+ Select the reason why each of the following equalities is true. +
+
+
+
+
+ Putting it all together,
+
+ Suppose that
+ where the missing entries are:
+ In conclusion,
- The graph below shows the function
When
- As the value of
- Changing the value of
When
- As the value of
- Changing the value of
- Set
When
- For all the values
- For all the values
- Set
+ The graph below shows the function
When
+ As the value of
+ Changing the value of
When
+ As the value of
+ Changing the value of
+ Set
When
+ For all the values
+ For all the values
+ Set
- All of the following situations contain expressions which can be used to model temperature or population growth. In each situation, we will solve for the exact value of various unknown quantities. -
- -
- The temperature of a warming object in an oven is given by
- This means that when
- Determine the exact value of
-
- The temperature of a cooling object in a refrigerator is modeled by
-
- What is the long-term behavior of
-
- This means that after a long time, when
-
- Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
-
-
- Suppose that
-
+ All of the following situations contain expressions which can be used to model temperature or population growth. In each situation, we will solve for the exact value of various unknown quantities. +
+ +
+ The temperature of a warming object in an oven is given by
+ This means that when
+ Determine the exact value of
+
+ The temperature of a cooling object in a refrigerator is modeled by
+
+ What is the long-term behavior of
+
+ This means that after a long time, when
+
+ Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
+
+
+ Suppose that
+
- Complete each of the following statements with an appropriate number or the symbols infinity
.
-
-
-
-
-
- Note that when we write
-
-
- Note that when we write
-
- Note that when we write
+ Complete each of the following statements with an appropriate number or the symbols infinity
.
+
+
+
+
+
+ Note that when we write
+
+
+ Note that when we write
+
+ Note that when we write
- A piece of cardboard that is
- As shown in the diagram, let
-
-
-
- We know that the volume of a rectangular box is given by
-
-
-
-
+ A piece of cardboard that is
+ As shown in the diagram, let
+
+
+
+ We know that the volume of a rectangular box is given by
+
+
+
+
- Hit Check Work when you have adjusted the sliders so that the graph crosses the
- Hit Check Work when you have adjusted the sliders so that the graph crosses the
- Hit Check Work when you have adjusted the sliders so that the graph crosses the
- Recall from the definition of a polynoimal function what we mean by a
- Hit Check Work when you have adjusted the sliders so that the graph shows
- It is also possible to adjust the sliders so that the graph has exactly
- We say that a function has a
- Recall that
- Experiment with the sliders, and hit Check Work when
- Experiment with the sliders, and hit Check Work when
- What other numbers of turning points are possible for
- What long-range behavior is possible for
- Experiment with the sliders, and hit Check Work when
- Experiment with the sliders, and hit Check Work when
- Click on the box below to plot
-
-
- It also means that the long-range behavior of
- Can you see how this behavior affects the possible number of turning points from part b.? -
-
+ Hit Check Work when you have adjusted the sliders so that the graph crosses the
+ Hit Check Work when you have adjusted the sliders so that the graph crosses the
+ Hit Check Work when you have adjusted the sliders so that the graph crosses the
+ Recall from the definition of a polynoimal function what we mean by a
+ Hit Check Work when you have adjusted the sliders so that the graph shows
+ It is also possible to adjust the sliders so that the graph has exactly
+ We say that a function has a
+ Recall that
+ Experiment with the sliders, and hit Check Work when
+ Experiment with the sliders, and hit Check Work when
+ What other numbers of turning points are possible for
+ What long-range behavior is possible for
+ Experiment with the sliders, and hit Check Work when
+ Experiment with the sliders, and hit Check Work when
+ Click on the box below to plot
+
+
+ It also means that the long-range behavior of
+ Can you see how this behavior affects the possible number of turning points from part b.? +
+
- A drug company estimates that to produce a new drug, it will cost
-$ .
- Determine a formula for a function
-
-
- The drug company needs to sell the drug at a price of more than
-
-
-
-
- Our computations in b. and c. naturally lead us to define the average cost per gram
function,
- The average cost per gram of producing
- What can you say about the long-range behavior of
-
- In the context of this scenario, this means
+ A drug company estimates that to produce a new drug, it will cost
+$ .
+ Determine a formula for a function
+
+
+ The drug company needs to sell the drug at a price of more than
+
+
+
+
+ Our computations in b. and c. naturally lead us to define the average cost per gram
function,
+ The average cost per gram of producing
+ What can you say about the long-range behavior of
+
+ In the context of this scenario, this means
- Consider the rational function
-
-
- Type
-
- Complete the sentences below to explain why
- As
- As
- As
- Finally, the graph of
- Can you see all the behavior we just discussed, or only some of it? Remember that you can zoom in and out using the "+" and "-" in the lower right corner of the graph, and that the "O" returns to the original view.
-
+ Consider the rational function
+
+
+ Type
+
+ Complete the sentences below to explain why
+ As
+ As
+ As
+ Finally, the graph of
+ Can you see all the behavior we just discussed, or only some of it? Remember that you can zoom in and out using the "+" and "-" in the lower right corner of the graph, and that the "O" returns to the original view.
+
- Below is an image of a right triangle whose sides are labeled
- We will complete a sketch of a right triangle with one leg of length
- First, determine the exact values of the sides
-
-
- After answering all the questions in part a. correctly, you now have a correctly labeled right triangle meeting the specified conditions. -
-
- What is the exact value of
-
- What special angle from the unit circle is
-
- Use your answer to c. to rewrite your equation from b. using the arcsine function in the form
-
+ Below is an image of a right triangle whose sides are labeled
+ We will complete a sketch of a right triangle with one leg of length
+ First, determine the exact values of the sides
+
+
+ After answering all the questions in part a. correctly, you now have a correctly labeled right triangle meeting the specified conditions. +
+
+ What is the exact value of
+
+ What special angle from the unit circle is
+
+ Use your answer to c. to rewrite your equation from b. using the arcsine function in the form
+
- Consider the plot of the standard cosine function in the following figure along with the emphasized portion of the graph on
- Let
-
-
- We can see from the graph that
- This means that
- We know that
-
- Determine the exact values of each of the quantities below. -
-
-
-
-
-
+ Consider the plot of the standard cosine function in the following figure along with the emphasized portion of the graph on
+ Let
+
+
+ We can see from the graph that
+ This means that
+ We know that
+
+ Determine the exact values of each of the quantities below. +
+
+
+
+
+
- Below is an image of a right triangle whose sides are labeled
- We will complete a sketch of a right triangle with hypotenuse of length
- First, determine the exact values of the sides
-
-
- After answering all the questions in part a. correctly, you now have a correctly labeled right triangle meeting the specified conditions. -
-
- Determine the exact value of each of the six trigonometric functions evaluated at
- What are the exact and approximate measures of the two non-right angles in the triangle? -
-
-
-
+ Below is an image of a right triangle whose sides are labeled
+ We will complete a sketch of a right triangle with hypotenuse of length
+ First, determine the exact values of the sides
+
+
+ After answering all the questions in part a. correctly, you now have a correctly labeled right triangle meeting the specified conditions. +
+
+ Determine the exact value of each of the six trigonometric functions evaluated at
+ What are the exact and approximate measures of the two non-right angles in the triangle? +
+
+
+
- What follows is
- In each of the situations, you will end up with an image of a right triangle that satisfies the given conditions, and you will determine the requested missing information in the triangle. Assume that all angles are being considered in radian measure. -
-
-
- First, drag the point below until you have a right triangle with hypotenuse of length
- Once you have found such a triangle, use the coordinates of the point on the unit circle to determine and enter the lengths of the two legs. -
-- Can you find another such point on the circle and can you explain why that point also works? What are the lengths of its legs? -
-
- Determine the values of
-
-
- First, drag the point below until you have a right triangle with hypotenuse of length
- Once you have found such a triangle, use the coordinates of the point on the unit circle to determine and enter the lengths of the two legs. -
-
- Determine the values of
-
- -
-
- First, determine the values of the sides
-
- -
-- Then determine the exact measures of the two non-right angles. -
-
-
+ What follows is
+ In each of the situations, you will end up with an image of a right triangle that satisfies the given conditions, and you will determine the requested missing information in the triangle. Assume that all angles are being considered in radian measure. +
+
+
+ First, drag the point below until you have a right triangle with hypotenuse of length
+ Once you have found such a triangle, use the coordinates of the point on the unit circle to determine and enter the lengths of the two legs. +
++ Can you find another such point on the circle and can you explain why that point also works? What are the lengths of its legs? +
+
+ Determine the values of
+
+
+ First, drag the point below until you have a right triangle with hypotenuse of length
+ Once you have found such a triangle, use the coordinates of the point on the unit circle to determine and enter the lengths of the two legs. +
+
+ Determine the values of
+
+ +
+
+ First, determine the values of the sides
+
+ +
++ Then determine the exact measures of the two non-right angles. +
+
+
- Through the following questions, we work to understand the special values and overall behavior of the tangent function. -
- - -
- Use the unit circle below (not a computational device) to find the exact value of
- Move the square point to each of the above angles and an answer box will appear. Enter a simplified exact expression, not a decimal approximation. -
-
-
- What are three other input values
- Drag the point to the approximate location of
-
- A table of values appears below, including the values from the angles asked about in the first graph above after you've answered them correctly. -
- -
- Moreover, a graph of the values appears below, and you can click to show the function
- Use the graph and your work above to answer the following: -
-
-
-
-
+ Through the following questions, we work to understand the special values and overall behavior of the tangent function. +
+ + +
+ Use the unit circle below (not a computational device) to find the exact value of
+ Move the square point to each of the above angles and an answer box will appear. Enter a simplified exact expression, not a decimal approximation. +
+
+
+ What are three other input values
+ Drag the point to the approximate location of
+
+ A table of values appears below, including the values from the angles asked about in the first graph above after you've answered them correctly. +
+ +
+ Moreover, a graph of the values appears below, and you can click to show the function
+ Use the graph and your work above to answer the following: +
+
+
+
+
- What do we mean by the average rate of change of a function on an interval? -
-- What does the average rate of change of a function measure? How do we interpret its meaning in context? -
-- How is the average rate of change of a function connected to a line that passes through two points on the curve? -
-
- Given a function that models a certain phenomenon,
- it's natural to ask such questions as
- how is the function changing on a given interval
or
- on which interval is the function changing more rapidly?
- The concept of average rate of change
- enables us to make these questions more mathematically precise.
- Initially, we will focus on the average rate of change of an object moving along a straight-line path.
-
- For a function
- In the context of a function that measures height or position of a moving object at a given time,
- the meaning of the average rate of change of the function on a given interval is the average velocity feet per second
since the units on the numerator are feet
and on the denominator seconds
. Morever,
The average rate of change of
The average rate of change of an abstract function
- While the average rate of change of a position function tells us the moving object's average velocity, in other contexts, - the average rate of change of a function can be similarly defined and has a related interpretation. We make the following formal definition. -
- -
- For a function
- In every situation, the units on the average rate of change help us interpret its meaning,
- and those units are always units of output per unit of input.
- The average rate of change of a function on an interval gives us an excellent way to describe how the function behaves, on average. For instance, if we compute
- Finally, we can even use the average rate of change of a function to predict future behavior. Since the population was changing on average by
- We have already seen that it is natural to use words such as increasing
and decreasing
to describe a function's behavior. For instance, for the tennis ball whose height is modeled by
- We make the following formal definitions to clarify what it means to say that a function is increasing or decreasing. -
- -
- Let
- Similarly, we say that
- If we compute the average rate of change of a function on an interval, we can decide if the function is increasing or decreasing on average on the interval, but it takes more work
- It is helpful be able to connect information about a function's average rate of change and its graph. For instance, if we have determined that
-
- For a function
- The value of units of output per unit of input
.
-
- The value of
+ What do we mean by the average rate of change of a function on an interval? +
++ What does the average rate of change of a function measure? How do we interpret its meaning in context? +
++ How is the average rate of change of a function connected to a line that passes through two points on the curve? +
+
+ Given a function that models a certain phenomenon,
+ it's natural to ask such questions as
+ how is the function changing on a given interval
or
+ on which interval is the function changing more rapidly?
+ The concept of average rate of change
+ enables us to make these questions more mathematically precise.
+ Initially, we will focus on the average rate of change of an object moving along a straight-line path.
+
+ For a function
+ In the context of a function that measures height or position of a moving object at a given time,
+ the meaning of the average rate of change of the function on a given interval is the average velocity feet per second
since the units on the numerator are feet
and on the denominator seconds
. Morever,
The average rate of change of
The average rate of change of an abstract function
+ While the average rate of change of a position function tells us the moving object's average velocity, in other contexts, + the average rate of change of a function can be similarly defined and has a related interpretation. We make the following formal definition. +
+ +
+ For a function
+ In every situation, the units on the average rate of change help us interpret its meaning,
+ and those units are always units of output per unit of input.
+ The average rate of change of a function on an interval gives us an excellent way to describe how the function behaves, on average. For instance, if we compute
+ Finally, we can even use the average rate of change of a function to predict future behavior. Since the population was changing on average by
+ We have already seen that it is natural to use words such as increasing
and decreasing
to describe a function's behavior. For instance, for the tennis ball whose height is modeled by
+ We make the following formal definitions to clarify what it means to say that a function is increasing or decreasing. +
+ +
+ Let
+ Similarly, we say that
+ If we compute the average rate of change of a function on an interval, we can decide if the function is increasing or decreasing on average on the interval, but it takes more work
+ It is helpful be able to connect information about a function's average rate of change and its graph. For instance, if we have determined that
+
+ For a function
+ The value of units of output per unit of input
.
+
+ The value of
- How can we create new functions by adding, subtracting, multiplying, or dividing given functions? -
-- What are piecewise functions and what are different ways we can represent them? -
-
- In arithmetic, we execute processes where we take two numbers to generate a new number. For example,
- We can work similarly with functions. Indeed, we have already seen a sophisticated way to combine two functions to generate a new, related function through composition. If
- Just as we can add, subtract, multiply, and divide numbers, we can also add, subtract, multiply, and divide functions to create a new function from two or more given functions. -
- -- In most mathematics up until calculus, - the main object we study is numbers. - We ask questions such as -
- what number(s) form solutions to the equation
-
- what number is the slope of the line
-
- what number is generated as output by the function
-
-
- This changes in calculus. In calculus, the fundamental objects being studied are
- functions themselves. A function is a much more sophisticated mathematical object than a number,
- in part because a function can be thought of in terms of its graph, which is an infinite collection of ordered pairs of the form
- It is often helpful to look at a function's formula and observe algebraic structure. For instance, given the quadratic function
-
- We thus naturally arrive at the ideas of adding, subtracting, multiplying, or dividing two or more functions, and hence introduce the following definitions and notation. -
- -
- Let
- The
- The
- The
- The
- When we work in applied settings with functions that model phenomena in the world around us,
- it is often useful to think carefully about the units of various quantities.
- Analyzing units can help us both understand the algebraic structure of functions and the variables involved,
- as well as assist us in assigning meaning to quantities we compute.
- We have already seen this with the notion of average rate of change:
- if a function people per year,
- and the value of
- Say that an investor is regularly purchasing stock in a particular company.
- Solution. Observe that the units on shares
and the units on dollars per share
. Thus when we compute the product
- dollars
, which is the total value of held stock. Hence,
-
- In both abstract and applied settings, - we sometimes have to use different formulas on different intervals in order to define a function of interest. -
- -
- A familiar and important function that is defined piecewise
- is the absolute value function:
-
- The absolute value of a real number, denoted by
A plot of the absolute value function,
- The absolute value function is one example of a piecewise-defined function. The bracket
notation in
- As long as we are careful to make sure that each potential input has one and only one corresponding output, we can define a piecewise function using as many different functions on different intervals as we desire. -
- --
- Just as we can generate a new number by adding, subtracting, multiplying, or dividing two given numbers, we can generate a new function by adding, subtracting, multiplying, or dividing two given functions. For instance, if we know formulas, graphs, or tables for functions
- A piecewise function is a function whose formula consists of at least two different formulas in such a way that which formula applies depends on where the input falls in the domain. For example, given two functions
+ How can we create new functions by adding, subtracting, multiplying, or dividing given functions? +
++ What are piecewise functions and what are different ways we can represent them? +
+
+ In arithmetic, we execute processes where we take two numbers to generate a new number. For example,
+ We can work similarly with functions. Indeed, we have already seen a sophisticated way to combine two functions to generate a new, related function through composition. If
+ Just as we can add, subtract, multiply, and divide numbers, we can also add, subtract, multiply, and divide functions to create a new function from two or more given functions. +
+ ++ In most mathematics up until calculus, + the main object we study is numbers. + We ask questions such as +
+ what number(s) form solutions to the equation
+
+ what number is the slope of the line
+
+ what number is generated as output by the function
+
+
+ This changes in calculus. In calculus, the fundamental objects being studied are
+ functions themselves. A function is a much more sophisticated mathematical object than a number,
+ in part because a function can be thought of in terms of its graph, which is an infinite collection of ordered pairs of the form
+ It is often helpful to look at a function's formula and observe algebraic structure. For instance, given the quadratic function
+
+ We thus naturally arrive at the ideas of adding, subtracting, multiplying, or dividing two or more functions, and hence introduce the following definitions and notation. +
+ +
+ Let
+ The
+ The
+ The
+ The
+ When we work in applied settings with functions that model phenomena in the world around us,
+ it is often useful to think carefully about the units of various quantities.
+ Analyzing units can help us both understand the algebraic structure of functions and the variables involved,
+ as well as assist us in assigning meaning to quantities we compute.
+ We have already seen this with the notion of average rate of change:
+ if a function people per year,
+ and the value of
+ Say that an investor is regularly purchasing stock in a particular company.
+ Solution. Observe that the units on shares
and the units on dollars per share
. Thus when we compute the product
+ dollars
, which is the total value of held stock. Hence,
+
+ In both abstract and applied settings, + we sometimes have to use different formulas on different intervals in order to define a function of interest. +
+ +
+ A familiar and important function that is defined piecewise
+ is the absolute value function:
+
+ The absolute value of a real number, denoted by
A plot of the absolute value function,
+ The absolute value function is one example of a piecewise-defined function. The bracket
notation in
+ As long as we are careful to make sure that each potential input has one and only one corresponding output, we can define a piecewise function using as many different functions on different intervals as we desire. +
+ ++
+ Just as we can generate a new number by adding, subtracting, multiplying, or dividing two given numbers, we can generate a new function by adding, subtracting, multiplying, or dividing two given functions. For instance, if we know formulas, graphs, or tables for functions
+ A piecewise function is a function whose formula consists of at least two different formulas in such a way that which formula applies depends on where the input falls in the domain. For example, given two functions
- How does the process of function composition produce a new function from two other functions? -
-
- In the composite function inner
and outer
function? What role do the domain and codomain of
- How does the expression for
- Recall that a function, by definition, is a process that takes a collection of inputs and produces a corresponding collection of outputs in such a way that the process produces one and only one output value for any single input value. Because every function is a process, it makes sense to think that it may be possible to take two function processes and do one of the processes first, and then apply the second process to the result. -
- -
- Suppose we know that
- Since
- First, it's important to realize what the rule for to generate the output that corresponds to an input, take the input and square it, and then subtract
In symbols, we might express
-
- Now, observing that
- When we have a situation such as in composed two functions
. In addition, we use the notation
- Whenever we have two functions, say
- If
- We sometimes call inner function
and outer function
. It is important to note that the inner function is actually the first function that gets applied to a given input, and then outer function is applied to the output of the inner function. In addition, in order for a composite function to make sense, we need to ensure that the range of the inner function lies within the domain of the outer function so that the resulting composite function is defined at every possible input.
-
- In addition to the possibility that functions are given by formulas, - functions can be given by tables or graphs. - We can think about composite functions in these settings as well, - and the following activities prompt us to consider functions given in this way. -
- -
- Recall Dolbear's function,
- The Celsius and Fahrenheit temperature scales are connected by a linear function. Indeed, the function that converts Fahrenheit to Celsius is
-
- Recall that the average rate of change of a function
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
- To think about the interval
- In this most recent expression for
plays. In particular, to understand the expression for
- Suppose that
- By definition, we know that
-
- In
-
- When defined, the composition of two functions
- In the composite function inner
function is outer
function is
- Because the expression
+ How does the process of function composition produce a new function from two other functions? +
+
+ In the composite function inner
and outer
function? What role do the domain and codomain of
+ How does the expression for
+ Recall that a function, by definition, is a process that takes a collection of inputs and produces a corresponding collection of outputs in such a way that the process produces one and only one output value for any single input value. Because every function is a process, it makes sense to think that it may be possible to take two function processes and do one of the processes first, and then apply the second process to the result. +
+ +
+ Suppose we know that
+ Since
+ First, it's important to realize what the rule for to generate the output that corresponds to an input, take the input and square it, and then subtract
In symbols, we might express
+
+ Now, observing that
+ When we have a situation such as in composed two functions
. In addition, we use the notation
+ Whenever we have two functions, say
+ If
+ We sometimes call inner function
and outer function
. It is important to note that the inner function is actually the first function that gets applied to a given input, and then outer function is applied to the output of the inner function. In addition, in order for a composite function to make sense, we need to ensure that the range of the inner function lies within the domain of the outer function so that the resulting composite function is defined at every possible input.
+
+ In addition to the possibility that functions are given by formulas, + functions can be given by tables or graphs. + We can think about composite functions in these settings as well, + and the following activities prompt us to consider functions given in this way. +
+ +
+ Recall Dolbear's function,
+ The Celsius and Fahrenheit temperature scales are connected by a linear function. Indeed, the function that converts Fahrenheit to Celsius is
+
+ Recall that the average rate of change of a function
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
+ To think about the interval
+ In this most recent expression for
plays. In particular, to understand the expression for
+ Suppose that
+ By definition, we know that
+
+ In
+
+ When defined, the composition of two functions
+ In the composite function inner
function is outer
function is
+ Because the expression
- How can we use the mathematical idea of a function to represent the relationship between two changing quantities? -
-- What are some formal characteristics of an abstract mathematical function? how do we think differently about these characteristics in the context of a physical model? -
-
- A mathematical model is an abstract concept through which we use mathematical language and notation to describe a phenomenon in the world around us. One example of a mathematical model is found in Dolbear's Law
- For a mathematical model, we often seek an algebraic formula that captures observed behavior accurately and can be used to predict behavior not yet observed. For the data in
- The mathematical concept of a function
- For instance, Dolbear's Law in
for the Dolbear
function, we can represent the process of taking inputs (observed chirp rates) to outputs (corresponding temperatures) using arrows:
-
we can also use the equivalent notation
to indicate that Dolbear's Law takes an input of
to indicate that a certain temperature,
- Tables and graphs are particularly valuable ways to characterize and represent functions. For the current example, we summarize some of the data the Dolbear function generates in
Graph of data from the function
- When a point such as
.
-
- For most important concepts in mathematics, the mathematical community decides on formal definitions to ensure that we have a shared language of understanding. In this text, we will use the following definition of the term function
.
-
- A
- If we name a given function
and sometimes write
When a particular input value to
and read this symbolic notation as
- Let
- For the Dolbear function
means the collection of all real numbers
and is sometimes called interval notation
.all Fahrenheit temperatures
. The codomain of a function is the collection of possible outputs, which we distinguish from the collection of actual ouputs.
-
- Let
- In many situations, the range of a function is much more challenging to determine than its codomain. For the Dolbear function, the range is straightforward to find by using the graph shown in
- The range of any function is always a subset of the codomain. It is possible for the range to equal the codomain. -
- -
- Again, a mathematical model is an abstract concept through which we use mathematical language and notation to describe a phenomenon in the world around us. So far, we have considered two different examples: the Dolbear function,
- Calculus shows that for a tennis ball tossed vertically from a window
- We start with the abstract function
Graph of the function
- For this abstract function, its domain is all real numbers
since we may input any real number all real numbers.
Finally, from the graph and the data, we observe that the largest possible output of the function
indicates that there is no left-hand bound on the interval.
- Next, we turn our attention to the model
Graph of the model
- To this point in our discussion of functions, we have mostly focused on what the function process may model and what the domain, codomain, and range of a model or abstract function are. It is also important to take note of another part of
. Said differently, if a relationship or process ever associates a single input with two or more different outputs, the process cannot be a function.
-
- Is the relationship between people and phone numbers a function? -
- -- Solution. No, this relationship is not a function. A given individual person can be associated with more than one phone number, such as their cell phone and their work telephone. This means that we can't view phone numbers as a function of people: one input (a person) can lead to two different outputs (phone numbers). We also can't view people as a function of phone numbers, since more than one person can be associated with a phone number, such as when a family shares a single phone at home. -
-
- The relationship between
- Solution. The relationship between
- For a relationship or process to be a function, each individual input must be associated with one and only one output. Thus, the usual way that we demonstrate a relationship or process is not a function is to find a particular input that is associated with two or more outputs. When the relationship is given graphically, such as in the left graph in
- A graph in the plane represents a function if and only if every vertical line intersects the graph at most once. When the graph passes this test, the vertical coordinate of each point on the graph can be viewed as a function of the horizontal coordinate of the point. -
-
- Since the vertical line
- We conclude with a formal definition of the graph of a function. -
- -
- Let
- When we use a computing device such as Desmos to graph a function
-
- A function is a process that generates a relationship between two collections of quantities. The function associates each member of a collection of input values with one and only one member of the collection of output values. A function can be described or defined by words, by a table of values, by a graph, or by a formula. -
-- Functions may be viewed as mathematical objects worthy of study for their own sake and also as models that represent physical phenomena in the world around us. Every function or model has a domain (the set of possible or allowable input values), a codomain (the set of possible output values), and a range (the set of all actual output values). Both the codomain and range depend on the domain. For an abstract function, the domain is usually viewed as the largest reasonable collection of input values; for a function that models a physical phenomenon, the domain is usually determined by the context of possibilities for the input in the phenomenon being considered. -
-+ How can we use the mathematical idea of a function to represent the relationship between two changing quantities? +
++ What are some formal characteristics of an abstract mathematical function? how do we think differently about these characteristics in the context of a physical model? +
+
+ A mathematical model is an abstract concept through which we use mathematical language and notation to describe a phenomenon in the world around us. One example of a mathematical model is found in Dolbear's Law
+ For a mathematical model, we often seek an algebraic formula that captures observed behavior accurately and can be used to predict behavior not yet observed. For the data in
+ The mathematical concept of a function
+ For instance, Dolbear's Law in
for the Dolbear
function, we can represent the process of taking inputs (observed chirp rates) to outputs (corresponding temperatures) using arrows:
+
we can also use the equivalent notation
to indicate that Dolbear's Law takes an input of
to indicate that a certain temperature,
+ Tables and graphs are particularly valuable ways to characterize and represent functions. For the current example, we summarize some of the data the Dolbear function generates in
Graph of data from the function
+ When a point such as
.
+
+ For most important concepts in mathematics, the mathematical community decides on formal definitions to ensure that we have a shared language of understanding. In this text, we will use the following definition of the term function
.
+
+ A
+ If we name a given function
and sometimes write
When a particular input value to
and read this symbolic notation as
+ Let
+ For the Dolbear function
means the collection of all real numbers
and is sometimes called interval notation
.all Fahrenheit temperatures
. The codomain of a function is the collection of possible outputs, which we distinguish from the collection of actual ouputs.
+
+ Let
+ In many situations, the range of a function is much more challenging to determine than its codomain. For the Dolbear function, the range is straightforward to find by using the graph shown in
+ The range of any function is always a subset of the codomain. It is possible for the range to equal the codomain. +
+ +
+ Again, a mathematical model is an abstract concept through which we use mathematical language and notation to describe a phenomenon in the world around us. So far, we have considered two different examples: the Dolbear function,
+ Calculus shows that for a tennis ball tossed vertically from a window
+ We start with the abstract function
Graph of the function
+ For this abstract function, its domain is all real numbers
since we may input any real number all real numbers.
Finally, from the graph and the data, we observe that the largest possible output of the function
indicates that there is no left-hand bound on the interval.
+ Next, we turn our attention to the model
Graph of the model
+ To this point in our discussion of functions, we have mostly focused on what the function process may model and what the domain, codomain, and range of a model or abstract function are. It is also important to take note of another part of
. Said differently, if a relationship or process ever associates a single input with two or more different outputs, the process cannot be a function.
+
+ Is the relationship between people and phone numbers a function? +
+ ++ Solution. No, this relationship is not a function. A given individual person can be associated with more than one phone number, such as their cell phone and their work telephone. This means that we can't view phone numbers as a function of people: one input (a person) can lead to two different outputs (phone numbers). We also can't view people as a function of phone numbers, since more than one person can be associated with a phone number, such as when a family shares a single phone at home. +
+
+ The relationship between
+ Solution. The relationship between
+ For a relationship or process to be a function, each individual input must be associated with one and only one output. Thus, the usual way that we demonstrate a relationship or process is not a function is to find a particular input that is associated with two or more outputs. When the relationship is given graphically, such as in the left graph in
+ A graph in the plane represents a function if and only if every vertical line intersects the graph at most once. When the graph passes this test, the vertical coordinate of each point on the graph can be viewed as a function of the horizontal coordinate of the point. +
+
+ Since the vertical line
+ We conclude with a formal definition of the graph of a function. +
+ +
+ Let
+ When we use a computing device such as Desmos to graph a function
+
+ A function is a process that generates a relationship between two collections of quantities. The function associates each member of a collection of input values with one and only one member of the collection of output values. A function can be described or defined by words, by a table of values, by a graph, or by a formula. +
++ Functions may be viewed as mathematical objects worthy of study for their own sake and also as models that represent physical phenomena in the world around us. Every function or model has a domain (the set of possible or allowable input values), a codomain (the set of possible output values), and a range (the set of all actual output values). Both the codomain and range depend on the domain. For an abstract function, the domain is usually viewed as the largest reasonable collection of input values; for a function that models a physical phenomenon, the domain is usually determined by the context of possibilities for the input in the phenomenon being considered. +
+- If we have two quantities that are changing in tandem, how can we connect the quantities and understand how change in one affects the other? -
-- When the amount of water in a tank is changing, what behaviors can we observe? -
-- Mathematics is the art of making sense of patterns. One way that patterns arise is when two quantities are changing in tandem. In this setting, we may make sense of the situation by expressing the relationship between the changing quantities through words, through images, through data, or through a formula. -
- -
- In
A visual representation of the data in
- We can also represent this data in a graph by plotting ordered pairs
- Sometimes it is possible to use variables and one or more equations to connect quantities that are changing in tandem. In the aquarium example from the preview activity, we can observe that the volume,
- One of the ways that we make sense of mathematical ideas is to view them from multiple perspectives. We may use different means to establish different points of view: words, numerical data, graphs, or symbols. In addition, sometimes by changing our perspective within a particular approach we gain deeper insight. -
- -The empty conical tank.
-The conical tank, partially filled.
-
- If we consider the conical tank discussed in
- Note that at any time while the tank is being filled,
- This most recent equation helps us understand how
- With the equation
- Plotting this data on two different sets of axes, we see the different ways that bends down
as time passes.
-
Plotting
Plotting
- These different behaviors make sense because of the shape of the tank. Since at first there is less volume relative to depth near the cone's point, as water flows in at a constant rate, the water's height will rise quickly. But as time goes on and more water is added at the same rate, there is more space for the water to fill in order to make the water level rise, and thus the water's height rises more and more slowly as time passes. -
- --
- When two related quantities are changing in tandem, we can better understand how change in one affects the other by using data, graphs, words, or algebraic symbols to express the relationship between them. See, for instance,
- When the amount of water in a tank is changing, we can observe other quantities that change, depending on the shape of the tank. For instance, if the tank is conical, we can consider both the changing height of the water and the changing radius of the surface of the water. In addition, whenever we think about a quantity that is changing as time passes, we note that time itself is changing. -
-+ If we have two quantities that are changing in tandem, how can we connect the quantities and understand how change in one affects the other? +
++ When the amount of water in a tank is changing, what behaviors can we observe? +
++ Mathematics is the art of making sense of patterns. One way that patterns arise is when two quantities are changing in tandem. In this setting, we may make sense of the situation by expressing the relationship between the changing quantities through words, through images, through data, or through a formula. +
+ +
+ In
A visual representation of the data in
+ We can also represent this data in a graph by plotting ordered pairs
+ Sometimes it is possible to use variables and one or more equations to connect quantities that are changing in tandem. In the aquarium example from the preview activity, we can observe that the volume,
+ One of the ways that we make sense of mathematical ideas is to view them from multiple perspectives. We may use different means to establish different points of view: words, numerical data, graphs, or symbols. In addition, sometimes by changing our perspective within a particular approach we gain deeper insight. +
+ +The empty conical tank.
+The conical tank, partially filled.
+
+ If we consider the conical tank discussed in
+ Note that at any time while the tank is being filled,
+ This most recent equation helps us understand how
+ With the equation
+ Plotting this data on two different sets of axes, we see the different ways that bends down
as time passes.
+
Plotting
Plotting
+ These different behaviors make sense because of the shape of the tank. Since at first there is less volume relative to depth near the cone's point, as water flows in at a constant rate, the water's height will rise quickly. But as time goes on and more water is added at the same rate, there is more space for the water to fill in order to make the water level rise, and thus the water's height rises more and more slowly as time passes. +
+ ++
+ When two related quantities are changing in tandem, we can better understand how change in one affects the other by using data, graphs, words, or algebraic symbols to express the relationship between them. See, for instance,
+ When the amount of water in a tank is changing, we can observe other quantities that change, depending on the shape of the tank. For instance, if the tank is conical, we can consider both the changing height of the water and the changing radius of the surface of the water. In addition, whenever we think about a quantity that is changing as time passes, we note that time itself is changing. +
+- What does it mean to say that a given function has an inverse function? -
-- How can we determine whether or not a given function has a corresponding inverse function? -
-- When a function has an inverse function, what important properties does the inverse function have in comparison to the original function? -
-
- Because every function is a process that converts a collection of inputs to a corresponding collection of outputs, a natural question is: for a particular function, can we change perspective and think of the original function's outputs as the inputs for a reverse process?
- If we phrase this question algebraically, it is analogous to asking: given an equation that defines
- In
- Similar work is sometimes possible with other functions. When we can find a new function that reverses the process of the original function, we say that the original function has an inverse function
and make the following formal definition.
-
- Let
- Note particularly what the equation
- When a given function
.
. We similarly write that
- When a given function has an inverse function, it allows us to express the same relationship from two different points of view. For instance, if
- If
- It's important to note in If there exists
That is, we don't guarantee that an inverse function exists for a given function. Thus, we might ask: how can we determine whether or not a given function has a corresponding inverse function? As with many questions about functions, there are often three different possible ways to explore such a question: through a table, through a graph, or through an algebraic formula.
-
- Do the functions
- For any function, the question of whether or not it has an inverse comes down to whether or not the process of the function can be reliably reversed. For functions given in table form such as
- The function
- However, the function
- In
- Do the functions
- The graph that defines function
- The graph that defines function
- Recall that when a point such as
- If we attempt to change perspective and use the graph of
- On the other hand, provided that the behavior seen in the figure continues, the function
- The graphical observations that we made for the function
- A function whose graph lies in the
- Do the functions
- For any function of the form
- Taking
- We attempt similar reasoning for the second function,
- The graphs of
A plot of
A plot of
- When a function has an inverse function, we have observed several important relationships that hold between the original function and the corresponding inverse function. -
- -
- Let
-
-
- The functions
- If
- Consider the setting where
- The last item above leads to a special relationship between the graphs of
The graph of a function
-
- A given function
- We determine whether or not a given function
- A good summary of the properties of an inverse function is provided in the
+ What does it mean to say that a given function has an inverse function? +
++ How can we determine whether or not a given function has a corresponding inverse function? +
++ When a function has an inverse function, what important properties does the inverse function have in comparison to the original function? +
+
+ Because every function is a process that converts a collection of inputs to a corresponding collection of outputs, a natural question is: for a particular function, can we change perspective and think of the original function's outputs as the inputs for a reverse process?
+ If we phrase this question algebraically, it is analogous to asking: given an equation that defines
+ In
+ Similar work is sometimes possible with other functions. When we can find a new function that reverses the process of the original function, we say that the original function has an inverse function
and make the following formal definition.
+
+ Let
+ Note particularly what the equation
+ When a given function
.
. We similarly write that
+ When a given function has an inverse function, it allows us to express the same relationship from two different points of view. For instance, if
+ If
+ It's important to note in If there exists
That is, we don't guarantee that an inverse function exists for a given function. Thus, we might ask: how can we determine whether or not a given function has a corresponding inverse function? As with many questions about functions, there are often three different possible ways to explore such a question: through a table, through a graph, or through an algebraic formula.
+
+ Do the functions
+ For any function, the question of whether or not it has an inverse comes down to whether or not the process of the function can be reliably reversed. For functions given in table form such as
+ The function
+ However, the function
+ In
+ Do the functions
+ The graph that defines function
+ The graph that defines function
+ Recall that when a point such as
+ If we attempt to change perspective and use the graph of
+ On the other hand, provided that the behavior seen in the figure continues, the function
+ The graphical observations that we made for the function
+ A function whose graph lies in the
+ Do the functions
+ For any function of the form
+ Taking
+ We attempt similar reasoning for the second function,
+ The graphs of
A plot of
A plot of
+ When a function has an inverse function, we have observed several important relationships that hold between the original function and the corresponding inverse function. +
+ +
+ Let
+
+
+ The functions
+ If
+ Consider the setting where
+ The last item above leads to a special relationship between the graphs of
The graph of a function
+
+ A given function
+ We determine whether or not a given function
+ A good summary of the properties of an inverse function is provided in the
- What behavior of a function makes its graph a straight line? -
-- For a function whose graph is a straight line, what structure does its formula have? -
-- How can we interpret the slope of a linear function in applied contexts? -
-- Functions whose graphs are straight lines are both the simplest and the most important functions in mathematics. - Lines often model important phenomena, - and even when they don't directly model phenomena, - lines can often approximate other functions that do. - Whether a function's graph is a straight line or not is connected directly to its average rate of change. -
- -
- In
- A function
- From prior study, we already know a lot about linear functions. In this section, we work to understand some familiar properties in light of the new perspective of
- Let's suppose we know that a function
- Find a formula for a linear function
- Solution. Using
- Replacing
- A line with slope
- Visualizing the various components of point-slope form is important. For a line through
- We naturally use the terms increasing
and decreasing
as from
The point-slope form of a line's equation.
-The slope-intercept form of a line's equation.
-
- A special case arises when the known point on a line satisfies
of the line.
- For the line with slope
- Slope-intercept form follows from point-slope form from the fact that replacing
- If a line is in slope-intercept or point-slope form, it is useful to be able to quickly interpret key information about the line from the form of its equation. -
- -
- For the line given by
- Solution. This line is in point-slope form. Its slope is
- For the line given by
- Solution. This line is in slope-intercept form. Its slope is
- Since linear functions are defined by the property that their average rate of change is constant, linear functions perfectly model quantities that change at a constant rate. In context, we can often think of slope as a rate of change; analyzing units carefully often yields significant insight. -
- -
- The Dolbear function
- Recall that units of output per unit of input
, and thus degrees Fahrenheit per chirp per minute
. This tells us that the average rate of change of the temperature function is
- Indeed, we can observe this through function values. We note that
The linear Dolbear function with slope
- Like with the Dolbear function, it is often useful to write a linear function (whose output is called
-
- The constant starting value
of the output that corresponds to an input of
- The constant
- The variable
- The variable
-
- Any function
- A linear function
- In an applied context where we have a linear function that models a phenomenon in the world around us, the slope tells us the function's (constant) average rate of change. The units on the slope, units of output per unit of input
and this enables us to articulate how the output changes in response to a
+ What behavior of a function makes its graph a straight line? +
++ For a function whose graph is a straight line, what structure does its formula have? +
++ How can we interpret the slope of a linear function in applied contexts? +
++ Functions whose graphs are straight lines are both the simplest and the most important functions in mathematics. + Lines often model important phenomena, + and even when they don't directly model phenomena, + lines can often approximate other functions that do. + Whether a function's graph is a straight line or not is connected directly to its average rate of change. +
+ +
+ In
+ A function
+ From prior study, we already know a lot about linear functions. In this section, we work to understand some familiar properties in light of the new perspective of
+ Let's suppose we know that a function
+ Find a formula for a linear function
+ Solution. Using
+ Replacing
+ A line with slope
+ Visualizing the various components of point-slope form is important. For a line through
+ We naturally use the terms increasing
and decreasing
as from
The point-slope form of a line's equation.
+The slope-intercept form of a line's equation.
+
+ A special case arises when the known point on a line satisfies
of the line.
+ For the line with slope
+ Slope-intercept form follows from point-slope form from the fact that replacing
+ If a line is in slope-intercept or point-slope form, it is useful to be able to quickly interpret key information about the line from the form of its equation. +
+ +
+ For the line given by
+ Solution. This line is in point-slope form. Its slope is
+ For the line given by
+ Solution. This line is in slope-intercept form. Its slope is
+ Since linear functions are defined by the property that their average rate of change is constant, linear functions perfectly model quantities that change at a constant rate. In context, we can often think of slope as a rate of change; analyzing units carefully often yields significant insight. +
+ +
+ The Dolbear function
+ Recall that units of output per unit of input
, and thus degrees Fahrenheit per chirp per minute
. This tells us that the average rate of change of the temperature function is
+ Indeed, we can observe this through function values. We note that
The linear Dolbear function with slope
+ Like with the Dolbear function, it is often useful to write a linear function (whose output is called
+
+ The constant starting value
of the output that corresponds to an input of
+ The constant
+ The variable
+ The variable
+
+ Any function
+ A linear function
+ In an applied context where we have a linear function that models a phenomenon in the world around us, the slope tells us the function's (constant) average rate of change. The units on the slope, units of output per unit of input
and this enables us to articulate how the output changes in response to a
- What patterns can we observe in how a quadratic function changes? -
-- What are familiar and important properties of quadratic functions? -
-- How can quadratic functions be used to model objects falling under the influence of gravity? -
-
- After linear functions,
- quadratic functions are arguably the next simplest functions in mathematics.
- A quadratic function
- Quadratic functions are likely familiar to you from experience in previous courses. Throughout, we let
- Because quadratic functions are familiar to us, we will quickly restate some of their important known properties. -
- -
- Let
- As we can see in
Three examples of quadratic functions that open up.
-One example of a quadratic function that opens down.
-
- While the quadratic formula will always provide any real solutions to
- Every quadratic function has a
- In addition, every quadratic function has a symmetric graph that either always curves upward or always curves downward. The graph opens upward if and only if
- The quadratic function
The vertex of a quadratic function that opens up.
-The vertex of a quadratic function that opens down.
-
- Note particularly that due to symmetry, the vertex of a quadratic function lies halfway between its
- Consider the quadratic function in standard form given by
- We first observe that we can write
- Next, observe that the vertex of
- Finally, the form
- In
- A quadratic function with vertex
- One of the reasons that quadratic functions are so important is because of a physical fact of the universe we inhabit:
- for an object only being influenced by gravity,
- One of the fantastic consequences of calculus
- For an object tossed vertically from an initial height of
- If height is measured instead in meters and velocity in meters per second, the gravitational constant is
- So far, we've seen that quadratic functions have many interesting properties. In
- Recall that we considered a water balloon tossed vertically from a fifth story window whose height,
- In
notation and focus on the starting value of each interval, viewing the resulting average rate of change,
Plot of
- Indeed, viewing this data graphically as in
- A key closing observation here is that the fact the parabola bends down
is apparently connected to the fact that its average rate of change decreases as we move left to right. By contrast, for a quadratic function that bends up
, we can show that its average rate of change increases as we move left to right (see
- For any function that consistently bends either exclusively upward or exclusively downward on a given interval
- If a function
- Thus, we now call a quadratic function concave up
, while if concave down
.
-
-
- Quadratic functions (of the form
- For an object with height
- A quadratic function
+ What patterns can we observe in how a quadratic function changes? +
++ What are familiar and important properties of quadratic functions? +
++ How can quadratic functions be used to model objects falling under the influence of gravity? +
+
+ After linear functions,
+ quadratic functions are arguably the next simplest functions in mathematics.
+ A quadratic function
+ Quadratic functions are likely familiar to you from experience in previous courses. Throughout, we let
+ Because quadratic functions are familiar to us, we will quickly restate some of their important known properties. +
+ +
+ Let
+ As we can see in
Three examples of quadratic functions that open up.
+One example of a quadratic function that opens down.
+
+ While the quadratic formula will always provide any real solutions to
+ Every quadratic function has a
+ In addition, every quadratic function has a symmetric graph that either always curves upward or always curves downward. The graph opens upward if and only if
+ The quadratic function
The vertex of a quadratic function that opens up.
+The vertex of a quadratic function that opens down.
+
+ Note particularly that due to symmetry, the vertex of a quadratic function lies halfway between its
+ Consider the quadratic function in standard form given by
+ We first observe that we can write
+ Next, observe that the vertex of
+ Finally, the form
+ In
+ A quadratic function with vertex
+ One of the reasons that quadratic functions are so important is because of a physical fact of the universe we inhabit:
+ for an object only being influenced by gravity,
+ One of the fantastic consequences of calculus
+ For an object tossed vertically from an initial height of
+ If height is measured instead in meters and velocity in meters per second, the gravitational constant is
+ So far, we've seen that quadratic functions have many interesting properties. In
+ Recall that we considered a water balloon tossed vertically from a fifth story window whose height,
+ In
notation and focus on the starting value of each interval, viewing the resulting average rate of change,
Plot of
+ Indeed, viewing this data graphically as in
+ A key closing observation here is that the fact the parabola bends down
is apparently connected to the fact that its average rate of change decreases as we move left to right. By contrast, for a quadratic function that bends up
, we can show that its average rate of change increases as we move left to right (see
+ For any function that consistently bends either exclusively upward or exclusively downward on a given interval
+ If a function
+ Thus, we now call a quadratic function concave up
, while if concave down
.
+
+
+ Quadratic functions (of the form
+ For an object with height
+ A quadratic function
- How is the graph of
- What do we mean by transformations
of a given function
- In our preparation for calculus, we aspire to understand functions from a wide range of perspectives and to become familiar with a library of basic functions. So far, two basic families of functions we have considered are linear functions and quadratic functions, the simplest of which are parent
function as the most fundamental member of a family of functions, as well as how other similar but more complicated functions are the result of transforming the parent function.
-
- Informally, a transformation
-
- In
- We begin by summarizing two of our findings in
- Given a function
- As we found in our Desmos explorations in the preview activity, is especially helpful to see the effects of vertical translation dynamically. -
- -Interactive vertical translations demonstration (in the HTML version only).
- -
- Move the slider
- In a vertical translation, the graph of
A vertical translation,
A horizontal translation,
- In
- From an algebraic point of view, horizontal translations are slightly more complicated than vertical ones. Given
- Again, it's instructive to see the effects of horizontal translation dynamically. -
- -Interactive horizontal translations demonstration (in the HTML version only).
- -
- Move the slider by clicking and dragging on the red point to see how changing
- Overall, we have the following general principle. -
- -
- Given a function
- We emphasize that in the horizontal translation
- So far, we have seen the possible effects of adding a constant value to function's output (that is, the new expression
- Given the parent function
- We first investigate the effects of
The parent function
The parent function
- In contrast, the transformation
- To consider the situation where
- Finally, we also investigate the case where
- As with vertical and horizontal translation, it's particularly instructive to see the effects of vertical scaling in a dynamic way. -
- -Interactive vertical scaling demonstration (in the HTML version only).
- -
- Move the slider by clicking and dragging on the red point to see how changing
- We summarize and generalize our observations from
- Given a function
- Given a function
- In the final question of
- By the algebraic rule for
- add
- multiply the output of
- subtract
The parent function
The parent function
- Continuing, we now consider the function
The function
The function
- Finally, we arrive at
- While there are some transformations that can be executed in either order (such as a combination of a horizontal translation and a vertical translation, as seen in part (b) of
-
- The graph of
- A transformation of a given function
+ How is the graph of
+ What do we mean by transformations
of a given function
+ In our preparation for calculus, we aspire to understand functions from a wide range of perspectives and to become familiar with a library of basic functions. So far, two basic families of functions we have considered are linear functions and quadratic functions, the simplest of which are parent
function as the most fundamental member of a family of functions, as well as how other similar but more complicated functions are the result of transforming the parent function.
+
+ Informally, a transformation
+
+ In
+ We begin by summarizing two of our findings in
+ Given a function
+ As we found in our Desmos explorations in the preview activity, is especially helpful to see the effects of vertical translation dynamically. +
+ +Interactive vertical translations demonstration (in the HTML version only).
+ +
+ Move the slider
+ In a vertical translation, the graph of
A vertical translation,
A horizontal translation,
+ In
+ From an algebraic point of view, horizontal translations are slightly more complicated than vertical ones. Given
+ Again, it's instructive to see the effects of horizontal translation dynamically. +
+ +Interactive horizontal translations demonstration (in the HTML version only).
+ +
+ Move the slider by clicking and dragging on the red point to see how changing
+ Overall, we have the following general principle. +
+ +
+ Given a function
+ We emphasize that in the horizontal translation
+ So far, we have seen the possible effects of adding a constant value to function's output (that is, the new expression
+ Given the parent function
+ We first investigate the effects of
The parent function
The parent function
+ In contrast, the transformation
+ To consider the situation where
+ Finally, we also investigate the case where
+ As with vertical and horizontal translation, it's particularly instructive to see the effects of vertical scaling in a dynamic way. +
+ +Interactive vertical scaling demonstration (in the HTML version only).
+ +
+ Move the slider by clicking and dragging on the red point to see how changing
+ We summarize and generalize our observations from
+ Given a function
+ Given a function
+ In the final question of
+ By the algebraic rule for
+ add
+ multiply the output of
+ subtract
The parent function
The parent function
+ Continuing, we now consider the function
The function
The function
+ Finally, we arrive at
+ While there are some transformations that can be executed in either order (such as a combination of a horizontal translation and a vertical translation, as seen in part (b) of
+
+ The graph of
+ A transformation of a given function
- How do the three standard transformations (vertical translation, horizontal translation, and vertical scaling) affect the midline, amplitude, range, and period of sine and cosine curves? -
-- What algebraic transformation results in horizontal stretching or scaling of a function? -
-- How can we determine a formula involving sine or cosine that models any circular periodic function for which the midline, amplitude, period, and an anchor point are known? -
-
- Recall our work in
- We know that the standard functions
- Given real numbers
- In
A sequence of transformations of
- It is often useful to follow one particular point through a sequence of transformations. In
- While the sine and cosine functions extend infinitely in either direction, it's natural to think of the point starting point
of the cosine function, and similarly the point
- For example, in starting point
- There is one more very important transformation of a function that we've not yet explored. Given a function
- In the interactive
Interactive horizontal scaling demonstration (in the HTML version only).
- -
- Move the slider by clicking and dragging on the red point to see how changing
- By experimenting with the slider, we gain an intuitive sense for how the value of
- We can also understand this from the perspective of function composition. To evaluate
- Given a function
- While we will soon focus on horizontal stretches of the sine and cosine functions for the remainder of this section, it's important to note that horizontal scaling follows the same principles for any function we choose. -
- -
- Because the circumference of the unit circle is
- We begin by considering two basic examples. First, let
A plot of the parent function,
- From the graph, we see that
in
A plot of the parent function,
- On the other hand, if we let
- Our observations generalize for any positive constant
- For any constant
- Thus, if we know the
-
- Given real numbers
- Given a function
- Given any circular periodic function for which the midline, amplitude, period, and an anchor point are known, we can find a corresponding formula for the function of the form
-
+ How do the three standard transformations (vertical translation, horizontal translation, and vertical scaling) affect the midline, amplitude, range, and period of sine and cosine curves? +
++ What algebraic transformation results in horizontal stretching or scaling of a function? +
++ How can we determine a formula involving sine or cosine that models any circular periodic function for which the midline, amplitude, period, and an anchor point are known? +
+
+ Recall our work in
+ We know that the standard functions
+ Given real numbers
+ In
A sequence of transformations of
+ It is often useful to follow one particular point through a sequence of transformations. In
+ While the sine and cosine functions extend infinitely in either direction, it's natural to think of the point starting point
of the cosine function, and similarly the point
+ For example, in starting point
+ There is one more very important transformation of a function that we've not yet explored. Given a function
+ In the interactive
Interactive horizontal scaling demonstration (in the HTML version only).
+ +
+ Move the slider by clicking and dragging on the red point to see how changing
+ By experimenting with the slider, we gain an intuitive sense for how the value of
+ We can also understand this from the perspective of function composition. To evaluate
+ Given a function
+ While we will soon focus on horizontal stretches of the sine and cosine functions for the remainder of this section, it's important to note that horizontal scaling follows the same principles for any function we choose. +
+ +
+ Because the circumference of the unit circle is
+ We begin by considering two basic examples. First, let
A plot of the parent function,
+ From the graph, we see that
in
A plot of the parent function,
+ On the other hand, if we let
+ Our observations generalize for any positive constant
+ For any constant
+ Thus, if we know the
+
+ Given real numbers
+ Given a function
+ Given any circular periodic function for which the midline, amplitude, period, and an anchor point are known, we can find a corresponding formula for the function of the form
+
- What is the radian measure of an angle? -
-- Are there natural special points on the unit circle whose coordinates we can identify exactly? -
-- How can we determine arc length and the location of special points in circles other than the unit circle? -
-
- As demonstrated by several different examples in
- If we pick any point
Coordinates of a point on the unit circle.
-A point traversing the unit circle.
-
- To study the circular functions generated by the unit circle, we will also animate a point and let it traverse the circle. Starting at
- In
- An angle whose vertex is at the center of a circle
- As seen in
- Since there are
- An angle whose radian measure is
- Note that in
- Our in-depth study of the unit circle is motivated by our desire to better understand the behavior of circular functions. Recall that as we traverse a circle, the height of the point moving along the circle generates a function that depends on distance traveled along the circle. Wherever possible, we'd like to be able to identify the exact height of a given point on the unit circle. Two special right triangles enable us to locate exactly an important collection of points on the unit circle. -
- -
- Our work in
The unit circle with
- In addition, we note that there are four additional points on the circle that we can locate exactly: the four points that correspond to angle measures of
- Finally, we note that we can identify any point on the unit circle exactly simply by choosing one of its coordinates. Since every point
- All of our work with the unit circle can be extended to circles centered at the origin with different radii, since a circle with a larger or smaller radius is a scaled version of the unit circle. For instance, if we instead consider a circle of radius
- If we think more generally about a circle of radius
- If a central angle measuring
- In the unit circle, where
-
- The radian measure of an angle connects the measure of a central angle in a circle to the radius of the circle. A central angle has radian measure
- If we begin at the point
- In any circle of radius
+ What is the radian measure of an angle? +
++ Are there natural special points on the unit circle whose coordinates we can identify exactly? +
++ How can we determine arc length and the location of special points in circles other than the unit circle? +
+
+ As demonstrated by several different examples in
+ If we pick any point
Coordinates of a point on the unit circle.
+A point traversing the unit circle.
+
+ To study the circular functions generated by the unit circle, we will also animate a point and let it traverse the circle. Starting at
+ In
+ An angle whose vertex is at the center of a circle
+ As seen in
+ Since there are
+ An angle whose radian measure is
+ Note that in
+ Our in-depth study of the unit circle is motivated by our desire to better understand the behavior of circular functions. Recall that as we traverse a circle, the height of the point moving along the circle generates a function that depends on distance traveled along the circle. Wherever possible, we'd like to be able to identify the exact height of a given point on the unit circle. Two special right triangles enable us to locate exactly an important collection of points on the unit circle. +
+ +
+ Our work in
The unit circle with
+ In addition, we note that there are four additional points on the circle that we can locate exactly: the four points that correspond to angle measures of
+ Finally, we note that we can identify any point on the unit circle exactly simply by choosing one of its coordinates. Since every point
+ All of our work with the unit circle can be extended to circles centered at the origin with different radii, since a circle with a larger or smaller radius is a scaled version of the unit circle. For instance, if we instead consider a circle of radius
+ If we think more generally about a circle of radius
+ If a central angle measuring
+ In the unit circle, where
+
+ The radian measure of an angle connects the measure of a central angle in a circle to the radius of the circle. A central angle has radian measure
+ If we begin at the point
+ In any circle of radius
- Why can every exponential function of form
- What is the natural base
- We have observed that the behavior of functions of the form
Plots of four different exponential functions of form
- Because the point
- In
: we could similarly write any function
- Through the central topic of the rate of change of a function, calculus helps us decide which base is best to use to represent all exponential functions. While we study average rate of change extensively in this course, in calculus there is more emphasis on the instantaneous rate of change. In that context, a natural question arises: is there a nonzero function that grows in such a way that its height is exactly how fast its height is increasing? -
- -
- Amazingly, it turns out that the answer to this questions is yes,
and the function with this property is
-
- The number
- For instance,
- Initially, it's important to note that
Plot of
- If we compare the graphs and some selected outputs of each function, as in
- In
- By the rules of exponents, we can rewrite this last equation equivalently as
-
- Given
A plot of
- In
- It follows that the function
- Any exponential function
- The natural base
+ Why can every exponential function of form
+ What is the natural base
+ We have observed that the behavior of functions of the form
Plots of four different exponential functions of form
+ Because the point
+ In
: we could similarly write any function
+ Through the central topic of the rate of change of a function, calculus helps us decide which base is best to use to represent all exponential functions. While we study average rate of change extensively in this course, in calculus there is more emphasis on the instantaneous rate of change. In that context, a natural question arises: is there a nonzero function that grows in such a way that its height is exactly how fast its height is increasing? +
+ +
+ Amazingly, it turns out that the answer to this questions is yes,
and the function with this property is
+
+ The number
+ For instance,
+ Initially, it's important to note that
Plot of
+ If we compare the graphs and some selected outputs of each function, as in
+ In
+ By the rules of exponents, we can rewrite this last equation equivalently as
+
+ Given
A plot of
+ In
+ It follows that the function
+ Any exponential function
+ The natural base
- What does it mean to say that a function is exponential
?
-
- How much data do we need to know in order to determine the formula for an exponential function? -
-- Are there important trends that all exponential functions exhibit? -
-
- Linear functions have constant average rate of change and model many important phenomena. In other settings, it is natural for a quantity to change at a rate that is proportional to the amount of the quantity present. For instance, whether you put $
- Suppose that a certain mutual fund has a
- If we repeat our computations for the second year, we observe that
-
- Of course, in
- In exponential function
.
-
- Let
- For an exponential function
- Because we will be frequently interested in functions such as exponential
, understanding that technically these are vertical stretches of exponential functions according to growth factor
of exponential growth
, wherease if exponential decay
.
- We explore the properties of functions of form
- To better understand the roles that
- In
- In contrast, the function
- If we know that a certain function is linear, it suffices to know two points that lie on the line to determine the function's formula. It turns out that exponential functions are similar: knowing two points on the graph of a function known to be exponential is enough information to determine the function's formula. In the following example, we show how knowing two values of an exponential function enables us to find both
- Suppose that
- Since we know that
Plot of
- Recall that a function is increasing on an interval if its value always increases as we move from left to right. Similarly, a function is decreasing on an interval provided that its value always decreases as we move from left to right. -
- -The exponential function
The exponential function
- If we consider an exponential function
- An additional trend is apparent in the graphs in
- From the data in increasing at an increasing rate
. For the function decreasing at an increasing rate
. These trends hold for exponential functions generally
- For an exponential function of the form
- if
- if
- Observe how a function's average rate of change helps us classify the function's behavior on an interval: whether the average rate of change is always positive or always negative on the interval enables us to say if the function is always increasing or always decreasing, and then how the average rate of change itself changes enables us to potentially say how the function is increasing or decreasing through phrases such as decreasing at an increasing rate
.
-
-
- We say that a function is exponential whenever its algebraic form is exponential
we include vertical stretches of these functions and thus allow
- To determine the formula for an exponential function of form
- If we know the amount,
- If we know any two points on the exponential function's graph, then we can set up a system of two equations in two unknowns and solve for both
- Exponential functions of the form
-
- The domain of any exponential function is the set of all real numbers and the range of any exponential function is the set of all positive real numbers. -
-
- The
- If
+ What does it mean to say that a function is exponential
?
+
+ How much data do we need to know in order to determine the formula for an exponential function? +
++ Are there important trends that all exponential functions exhibit? +
+
+ Linear functions have constant average rate of change and model many important phenomena. In other settings, it is natural for a quantity to change at a rate that is proportional to the amount of the quantity present. For instance, whether you put $
+ Suppose that a certain mutual fund has a
+ If we repeat our computations for the second year, we observe that
+
+ Of course, in
+ In exponential function
.
+
+ Let
+ For an exponential function
+ Because we will be frequently interested in functions such as exponential
, understanding that technically these are vertical stretches of exponential functions according to growth factor
of exponential growth
, wherease if exponential decay
.
+ We explore the properties of functions of form
+ To better understand the roles that
+ In
+ In contrast, the function
+ If we know that a certain function is linear, it suffices to know two points that lie on the line to determine the function's formula. It turns out that exponential functions are similar: knowing two points on the graph of a function known to be exponential is enough information to determine the function's formula. In the following example, we show how knowing two values of an exponential function enables us to find both
+ Suppose that
+ Since we know that
Plot of
+ Recall that a function is increasing on an interval if its value always increases as we move from left to right. Similarly, a function is decreasing on an interval provided that its value always decreases as we move from left to right. +
+ +The exponential function
The exponential function
+ If we consider an exponential function
+ An additional trend is apparent in the graphs in
+ From the data in increasing at an increasing rate
. For the function decreasing at an increasing rate
. These trends hold for exponential functions generally
+ For an exponential function of the form
+ if
+ if
+ Observe how a function's average rate of change helps us classify the function's behavior on an interval: whether the average rate of change is always positive or always negative on the interval enables us to say if the function is always increasing or always decreasing, and then how the average rate of change itself changes enables us to potentially say how the function is increasing or decreasing through phrases such as decreasing at an increasing rate
.
+
+
+ We say that a function is exponential whenever its algebraic form is exponential
we include vertical stretches of these functions and thus allow
+ To determine the formula for an exponential function of form
+ If we know the amount,
+ If we know any two points on the exponential function's graph, then we can set up a system of two equations in two unknowns and solve for both
+ Exponential functions of the form
+
+ The domain of any exponential function is the set of all real numbers and the range of any exponential function is the set of all positive real numbers. +
+
+ The
+ If
- What structural rules do logarithms obey that are similar to rules for exponents? -
-- What are the key properties of the graph of the natural logarithm function? -
-- How do logarithms enable us to solve exponential equations? -
-
- Logarithms arise as inverses of exponential functions. In addition, we have motivated their development by our desire to solve exponential equations such as
- In
- Let
- A similar property holds for
- We have thus shown the following general principles. -
- -
- For any positive real numbers
- Because positive integer exponents are a shorthand way to express repeated multiplication, we can use the multiplication rule for logarithms to think about exponents as well. For example,
-
- For any positive real number
- The rule that
- Solve the equation
- To solve for
- The approach used in
- As the inverse of the natural exponential function
The natural exponential and natural logarithm functions on the interval
The natural exponential and natural logarithm functions on the interval
- Indeed, for any point
- The graph of
- passes through the point
- is always increasing; -
-- is always concave down; and -
-- increases without bound. -
-
- Because the graph of
- While the natural exponential function and the natural logarithm (and transformations of these functions) are connected and have certain similar properties, it's also important to be able to distinguish between behavior that is fundamentally exponential and fundamentally logarithmic. -
- -
- We've seen in several different settings that the function
- A population of bacteria cells is growing at a rate proportionate to the number of cells present at a given time
- Since the model has form
- To determine how long it takes for the population to reach
- There are three fundamental rules for exponents given nonzero base
- The natural logarithm's domain is the set of all positive real numbers and its range is the set of all real numbers. Its graph passes through
- Logarithms are very important in determining values that arise in equations of the form
-
+ What structural rules do logarithms obey that are similar to rules for exponents? +
++ What are the key properties of the graph of the natural logarithm function? +
++ How do logarithms enable us to solve exponential equations? +
+
+ Logarithms arise as inverses of exponential functions. In addition, we have motivated their development by our desire to solve exponential equations such as
+ In
+ Let
+ A similar property holds for
+ We have thus shown the following general principles. +
+ +
+ For any positive real numbers
+ Because positive integer exponents are a shorthand way to express repeated multiplication, we can use the multiplication rule for logarithms to think about exponents as well. For example,
+
+ For any positive real number
+ The rule that
+ Solve the equation
+ To solve for
+ The approach used in
+ As the inverse of the natural exponential function
The natural exponential and natural logarithm functions on the interval
The natural exponential and natural logarithm functions on the interval
+ Indeed, for any point
+ The graph of
+ passes through the point
+ is always increasing; +
++ is always concave down; and +
++ increases without bound. +
+
+ Because the graph of
+ While the natural exponential function and the natural logarithm (and transformations of these functions) are connected and have certain similar properties, it's also important to be able to distinguish between behavior that is fundamentally exponential and fundamentally logarithmic. +
+ +
+ We've seen in several different settings that the function
+ A population of bacteria cells is growing at a rate proportionate to the number of cells present at a given time
+ Since the model has form
+ To determine how long it takes for the population to reach
+ There are three fundamental rules for exponents given nonzero base
+ The natural logarithm's domain is the set of all positive real numbers and its range is the set of all real numbers. Its graph passes through
+ Logarithms are very important in determining values that arise in equations of the form
+
- How is the base-
- What is the natural logarithm
and how is it different from the base-
- How can we solve an equation that involves
- In undo
one another's respective processes. In other words, the process of the function
- More formally, recall that a function
- The powers-of-
- Given a positive real number
to denote the base-
- The base-
- In the notation of logarithms, we can now update our earlier observations with the functions
, while the second says
. Similarly,
-
- If we rearrange the statements of the facts in the power to which we raise
. That is, the base-
- In a similar way, if we rearrange the statements in when
.
-
- We summarize the key relationships between the powers-of-
-
- The domain of
- The domain of
- For any real number
- For any positive real number
-
- The base-
- It's important to note that the logarithm function produces exact values. For instance, if we want to solve the equation
- The base-
- Given a positive real number
to denote the natural logarithm of
- We can think of the natural logarithm, base-
. For instance,
- the power to which we raise
; the latter equation is true since when we raise
. The key relationships between the natural exponential and the natural logarithm function are investigated in
- In
- Determine the exact value of
- Solution. Since we want
- In modeling important phenomena using exponential functions, we will frequently encounter equations where the variable is in the exponent, like in
- The base-
- The natural logarithm
- The natural logarithm often enables us to solve an equation that involves
. We know that it is equivalent to say
-
+ How is the base-
+ What is the natural logarithm
and how is it different from the base-
+ How can we solve an equation that involves
+ In undo
one another's respective processes. In other words, the process of the function
+ More formally, recall that a function
+ The powers-of-
+ Given a positive real number
to denote the base-
+ The base-
+ In the notation of logarithms, we can now update our earlier observations with the functions
, while the second says
. Similarly,
+
+ If we rearrange the statements of the facts in the power to which we raise
. That is, the base-
+ In a similar way, if we rearrange the statements in when
.
+
+ We summarize the key relationships between the powers-of-
+
+ The domain of
+ The domain of
+ For any real number
+ For any positive real number
+
+ The base-
+ It's important to note that the logarithm function produces exact values. For instance, if we want to solve the equation
+ The base-
+ Given a positive real number
to denote the natural logarithm of
+ We can think of the natural logarithm, base-
. For instance,
+ the power to which we raise
; the latter equation is true since when we raise
. The key relationships between the natural exponential and the natural logarithm function are investigated in
+ In
+ Determine the exact value of
+ Solution. Since we want
+ In modeling important phenomena using exponential functions, we will frequently encounter equations where the variable is in the exponent, like in
+ The base-
+ The natural logarithm
+ The natural logarithm often enables us to solve an equation that involves
. We know that it is equivalent to say
+
- What can we say about the behavior of an exponential function as the input gets larger and larger? -
-- How do vertical stretches and shifts of an exponential function affect its behavior? -
-
- Why is the temperature of a cooling or warming object modeled by a function of the form
- If a quantity changes so that its growth or decay occurs at a constant percentage rate with respect to time, the function is exponential. This is because if the growth or decay rate is
- A related situation arises when an object's temperature changes in response to its surroundings. For instance, if we have a cup of coffee at an initial temperature of
A plot of the data in
- In one sense, the data looks exponential: the points appear to lie on a curve that is always decreasing and decreasing at an increasing rate. However, we know that the function can't have the form
- We have already established that any exponential function of the form
- For the increasing function
- For the decreasing function
- To represent these two common phenomena with exponential functions
as
as
- In
- Let
- If
-
- If
-
- In addition, we make a key observation about the use of exponents. For the function
Plots of
- Similar observations hold for the relationship between the graphs of
- The function
Plot of
Plot of
- Let
- If
- If
- It is also possible to have
- It's an important skill to be able to look at an exponential function of the form
- Newton's Law of Cooling
- The data in the bottom row of
Plot of
Plot of
- If we choose two of the data points, say
- Our preceding work with the coffee data can be done similarly with data for any cooling or warming object whose temperature initially differs from its surroundings. Indeed, it is possible to show that Newton's Law of Cooling implies that the object's temperature is given by a function of the form
-
- For an exponential function of the form
- The function
- In the situation where
- An exponential function can be thought of as a function that changes at a rate proportional to itself, like how money grows with compound interest or the amount of a radioactive quantity decays. Newton's Law of Cooling says that the rate of change of an object's temperature is proportional to the difference between its own temperature and the temperature of its surroundings. This leads to the function that measures the difference between the object's temperature and room temperature being exponential, and hence the object's temperature itself is a vertically-shifted exponential function of the form
+ What can we say about the behavior of an exponential function as the input gets larger and larger? +
++ How do vertical stretches and shifts of an exponential function affect its behavior? +
+
+ Why is the temperature of a cooling or warming object modeled by a function of the form
+ If a quantity changes so that its growth or decay occurs at a constant percentage rate with respect to time, the function is exponential. This is because if the growth or decay rate is
+ A related situation arises when an object's temperature changes in response to its surroundings. For instance, if we have a cup of coffee at an initial temperature of
A plot of the data in
+ In one sense, the data looks exponential: the points appear to lie on a curve that is always decreasing and decreasing at an increasing rate. However, we know that the function can't have the form
+ We have already established that any exponential function of the form
+ For the increasing function
+ For the decreasing function
+ To represent these two common phenomena with exponential functions
as
as
+ In
+ Let
+ If
+
+ If
+
+ In addition, we make a key observation about the use of exponents. For the function
Plots of
+ Similar observations hold for the relationship between the graphs of
+ The function
Plot of
Plot of
+ Let
+ If
+ If
+ It is also possible to have
+ It's an important skill to be able to look at an exponential function of the form
+ Newton's Law of Cooling
+ The data in the bottom row of
Plot of
Plot of
+ If we choose two of the data points, say
+ Our preceding work with the coffee data can be done similarly with data for any cooling or warming object whose temperature initially differs from its surroundings. Indeed, it is possible to show that Newton's Law of Cooling implies that the object's temperature is given by a function of the form
+
+ For an exponential function of the form
+ The function
+ In the situation where
+ An exponential function can be thought of as a function that changes at a rate proportional to itself, like how money grows with compound interest or the amount of a radioactive quantity decays. Newton's Law of Cooling says that the rate of change of an object's temperature is proportional to the difference between its own temperature and the temperature of its surroundings. This leads to the function that measures the difference between the object's temperature and room temperature being exponential, and hence the object's temperature itself is a vertically-shifted exponential function of the form
- What roles do the parameters
- How can we use an exponential function to more realistically model a population whose growth levels off? -
-
- We've seen that exponential functions can be used to model several different important phenomena, such as the growth of money due to continuously compounded interest, the decay of radioactive quanitities, and the temperature of an object that is cooling or warming due to its surroundings. From initial work with functions of the form
- We have also begun to see the important role that logarithms play in work with exponential models. The natural logarithm is the inverse of the natural exponential function and satisfies the important rule that
- In
- In
- From
- For the function
- Since
- Since
- Once we know the values of
- If we assume that a population grows at a rate that is proportionate to the size of the population, it follows that the population grows exponentially according to the model
-
- In light of these observations, a different model is needed for population, one that grows exponentially at first, but that levels off later. Calculus can be used to develop such a model, and the resulting function is usually called the
-
- When a function of form
- Because the exponential function
+ What roles do the parameters
+ How can we use an exponential function to more realistically model a population whose growth levels off? +
+
+ We've seen that exponential functions can be used to model several different important phenomena, such as the growth of money due to continuously compounded interest, the decay of radioactive quanitities, and the temperature of an object that is cooling or warming due to its surroundings. From initial work with functions of the form
+ We have also begun to see the important role that logarithms play in work with exponential models. The natural logarithm is the inverse of the natural exponential function and satisfies the important rule that
+ In
+ In
+ From
+ For the function
+ Since
+ Since
+ Once we know the values of
+ If we assume that a population grows at a rate that is proportionate to the size of the population, it follows that the population grows exponentially according to the model
+
+ In light of these observations, a different model is needed for population, one that grows exponentially at first, but that levels off later. Calculus can be used to develop such a model, and the resulting function is usually called the
+
+ When a function of form
+ Because the exponential function
- How can we use limit notation to succinctly express a function's behavior as the input increases without bound or as the function's value increases without bound? -
-
- What are some important limits and trends involving
- What is a power function and how does the value of the power determine the function's overall behavior? -
-
- In
symbol to represent a quantity that gets larger and larger with no bound on its growth.
-
- We also know that the concept of infinity plays a key role in understanding the graphical behavior of functions. For instance, we've seen that for a function such as
- In
- When observing a pattern in the values of a function that correspond to letting the inputs get closer and closer to a fixed value or letting the inputs increase or decrease without bound, we are often interested in the behavior of the function in the limit
. In either case, we are considering an infinite collection of inputs that are themselves following a pattern, and we ask the question how can we expect the function's output to behave if we continue?
-
- For instance, we have regularly observed that as
which means that by allowing
Plots of
Plots of
- Similarly, as seen in
- Let
- If the value of
- Finally, if
- We use limit notation in related, natural ways to express patterns we see in function behavior. For instance, we write
- In the situation where
- For now, we are going to focus on the long-range behavior of certain basic, familiar functions and work to understand how they behave as the input increases or decreases without bound. Above we've used the input variable
- To date, we have worked with several families of functions:
- linear functions of form
A function of the form
- We first focus on the case where
- In the situation where the power
- The notation
-
- Similarly, the notation
-
- We summarize some key behavior of familiar basic functions with limits as
- Additionally,
- A power function is a function of the form
-
- If U-shaped
, while all power functions of form chair-shaped
.
-
- If
+ How can we use limit notation to succinctly express a function's behavior as the input increases without bound or as the function's value increases without bound? +
+
+ What are some important limits and trends involving
+ What is a power function and how does the value of the power determine the function's overall behavior? +
+
+ In
symbol to represent a quantity that gets larger and larger with no bound on its growth.
+
+ We also know that the concept of infinity plays a key role in understanding the graphical behavior of functions. For instance, we've seen that for a function such as
+ In
+ When observing a pattern in the values of a function that correspond to letting the inputs get closer and closer to a fixed value or letting the inputs increase or decrease without bound, we are often interested in the behavior of the function in the limit
. In either case, we are considering an infinite collection of inputs that are themselves following a pattern, and we ask the question how can we expect the function's output to behave if we continue?
+
+ For instance, we have regularly observed that as
which means that by allowing
Plots of
Plots of
+ Similarly, as seen in
+ Let
+ If the value of
+ Finally, if
+ We use limit notation in related, natural ways to express patterns we see in function behavior. For instance, we write
+ In the situation where
+ For now, we are going to focus on the long-range behavior of certain basic, familiar functions and work to understand how they behave as the input increases or decreases without bound. Above we've used the input variable
+ To date, we have worked with several families of functions:
+ linear functions of form
A function of the form
+ We first focus on the case where
+ In the situation where the power
+ The notation
+
+ Similarly, the notation
+
+ We summarize some key behavior of familiar basic functions with limits as
+ Additionally,
+ A power function is a function of the form
+
+ If U-shaped
, while all power functions of form chair-shaped
.
+
+ If
- Why do polynomials arise naturally in the study of problems involving the volume and surface area of three-dimensional containers such as boxes and cylinders? -
-- How can polynomial functions be used to approximate non-polynomial curves and functions? -
-
- Polynomial functions are the simplest of all functions in mathematics in part because they only involve multiplication and addition. In any applied setting where we can formulate key ideas using only those arithmetic operations, it's natural that polynomial functions model the corresponding phenomena. For example, in
- In other similar situations where we consider the volume of a box, tank, or other three-dimensional container, polynomial functions frequently arise. To develop a model function that represents a physical situation, we almost always begin by drawing one or more diagrams of the situation and then introduce one or more variables to represent quantities that are changing. From there, we explore relationships that are present and work to express one of the quantities in terms of the other(s). -
- -
- In
A rectangular box.
-A circular cylinder.
-
- One way to remember the formula for the volume of a rectangular box is area of the base times the height
. This principle extends to other three-dimensional shapes that have constant cross-sectional area. For instance, the volume of a circular cylinder with radius
- We'll also often consider the surface area of a three-dimensional container. For a rectangular box with side lengths of sides
. If we think of cutting the cylinder vertically and unfurling it, the resulting figure is a rectangle whose dimensions are the height of the cylinder,
- Each of the volume and surface area equations (
- A different use of polynomial functions arises with Bezier curves.
A cubic Bezier curve with control points in gray.
-The letter S in Palatino font, generated by Bezier curves.
-
- The main issue to realize is that the form of the curve depends on a special family of cubic polynomials:
-
- Another important application of polynomial functions is found in how they can be used to approximate the sine and cosine functions. -
- -
- Polynomials arise naturally in the study of problems involving the volume and surface area of three-dimensional containers such as boxes and cylinders because these formulas fundamentally involve sums and products of variables. For instance, the volume of a cylinder is
- Polynomial functions can be used to approximate non-polynomial curves and functions in many different ways. One example is found in cubic Bezier curves which use a collection of control points to enable the user to manipulate curves to pass through select points in such a way that the curve first travels in a certain direction. Another example is in the remarkable approximation of non-polynomial functions like the sine function, as given by
-
+ Why do polynomials arise naturally in the study of problems involving the volume and surface area of three-dimensional containers such as boxes and cylinders? +
++ How can polynomial functions be used to approximate non-polynomial curves and functions? +
+
+ Polynomial functions are the simplest of all functions in mathematics in part because they only involve multiplication and addition. In any applied setting where we can formulate key ideas using only those arithmetic operations, it's natural that polynomial functions model the corresponding phenomena. For example, in
+ In other similar situations where we consider the volume of a box, tank, or other three-dimensional container, polynomial functions frequently arise. To develop a model function that represents a physical situation, we almost always begin by drawing one or more diagrams of the situation and then introduce one or more variables to represent quantities that are changing. From there, we explore relationships that are present and work to express one of the quantities in terms of the other(s). +
+ +
+ In
A rectangular box.
+A circular cylinder.
+
+ One way to remember the formula for the volume of a rectangular box is area of the base times the height
. This principle extends to other three-dimensional shapes that have constant cross-sectional area. For instance, the volume of a circular cylinder with radius
+ We'll also often consider the surface area of a three-dimensional container. For a rectangular box with side lengths of sides
. If we think of cutting the cylinder vertically and unfurling it, the resulting figure is a rectangle whose dimensions are the height of the cylinder,
+ Each of the volume and surface area equations (
+ A different use of polynomial functions arises with Bezier curves.
A cubic Bezier curve with control points in gray.
+The letter S in Palatino font, generated by Bezier curves.
+
+ The main issue to realize is that the form of the curve depends on a special family of cubic polynomials:
+
+ Another important application of polynomial functions is found in how they can be used to approximate the sine and cosine functions. +
+ +
+ Polynomials arise naturally in the study of problems involving the volume and surface area of three-dimensional containers such as boxes and cylinders because these formulas fundamentally involve sums and products of variables. For instance, the volume of a cylinder is
+ Polynomial functions can be used to approximate non-polynomial curves and functions in many different ways. One example is found in cubic Bezier curves which use a collection of control points to enable the user to manipulate curves to pass through select points in such a way that the curve first travels in a certain direction. Another example is in the remarkable approximation of non-polynomial functions like the sine function, as given by
+
- What properties of a polynomial function can we deduce from its algebraic structure? -
-- What is a sign chart and how does it help us understand a polynomial function's behavior? -
-
- How do zeros of multiplicity other than
- We know that linear functions are the simplest of all functions we can consider: their graphs have the simplest shape, their average rate of change is always constant (regardless of the interval chosen), and their formula is elementary. Moreover, computing the value of a linear function only requires multiplication and addition. -
- -
- If we think of a linear function as having formula
- Indeed, if we instead view linear functions as having form
-
- Given real numbers
- The polyomial function
- Since a polynomial is simply a sum of constant multiples of various power functions with positive integer powers, we often refer to those individual terms by referring to their individual degrees: the linear term, the quadratic term, and so on. In addition, since the domain of any power function of the form
- Our observations in
- For any degree
- We know that each of the power functions
- For any degree U-shaped
(chair-shaped
(like
- In
Plot of a degree
Plot of the same degree
- Finally, a key idea from calculus justifies the fact that the maximum number of turning points of a degree
- For any degree
- Just like a quadratic function can be written in different forms (standard:
- The Zero Product Property
- Consider the polynomial function
- Since
- Since
- When
in that location on the sign chart pictured in
- In addition, since there are an even number of negative terms in the product, the overall product's sign is positive, which we indicate by the single
beneath
, and by writing POS
below the coordinate axis.
-
A sign chart for the polynomial function
- We now proceed to the other intervals created by the zeros. On
for this interval, which has overall sign
, as noted in the figure. Similar reasoning completes the diagram.
-
- From all of the information we have deduced about
The graph of the polynomial function
- In
- To see the impact of repeated factors, we examine a collection of degree
is repeated
- Next we consider the degree
A plot of
- Observe that in
A plot of
A plot of
- If we next let
Plot of
Plot of
- Finally, if we consider
Plot of
- Our observations with polynomials of degree
- If
-
- From a polynomial function's algebraic structure, we can deduce several key traits of the function. -
--
- If the function is in standard form, say
- If the function is in factored form, say
- A sign chart is a visual way to identify all of the locations where a function is zero along with the sign of the function on the various intervals the zeros create. A sign chart gives us an overall sense of the graph of the function, but without concerning ourselves with any specific values of the function besides the zeros. For a sample sign chart, see
- When a polynomial
+ What properties of a polynomial function can we deduce from its algebraic structure? +
++ What is a sign chart and how does it help us understand a polynomial function's behavior? +
+
+ How do zeros of multiplicity other than
+ We know that linear functions are the simplest of all functions we can consider: their graphs have the simplest shape, their average rate of change is always constant (regardless of the interval chosen), and their formula is elementary. Moreover, computing the value of a linear function only requires multiplication and addition. +
+ +
+ If we think of a linear function as having formula
+ Indeed, if we instead view linear functions as having form
+
+ Given real numbers
+ The polyomial function
+ Since a polynomial is simply a sum of constant multiples of various power functions with positive integer powers, we often refer to those individual terms by referring to their individual degrees: the linear term, the quadratic term, and so on. In addition, since the domain of any power function of the form
+ Our observations in
+ For any degree
+ We know that each of the power functions
+ For any degree U-shaped
(chair-shaped
(like
+ In
Plot of a degree
Plot of the same degree
+ Finally, a key idea from calculus justifies the fact that the maximum number of turning points of a degree
+ For any degree
+ Just like a quadratic function can be written in different forms (standard:
+ The Zero Product Property
+ Consider the polynomial function
+ Since
+ Since
+ When
in that location on the sign chart pictured in
+ In addition, since there are an even number of negative terms in the product, the overall product's sign is positive, which we indicate by the single
beneath
, and by writing POS
below the coordinate axis.
+
A sign chart for the polynomial function
+ We now proceed to the other intervals created by the zeros. On
for this interval, which has overall sign
, as noted in the figure. Similar reasoning completes the diagram.
+
+ From all of the information we have deduced about
The graph of the polynomial function
+ In
+ To see the impact of repeated factors, we examine a collection of degree
is repeated
+ Next we consider the degree
A plot of
+ Observe that in
A plot of
A plot of
+ If we next let
Plot of
Plot of
+ Finally, if we consider
Plot of
+ Our observations with polynomials of degree
+ If
+
+ From a polynomial function's algebraic structure, we can deduce several key traits of the function. +
++
+ If the function is in standard form, say
+ If the function is in factored form, say
+ A sign chart is a visual way to identify all of the locations where a function is zero along with the sign of the function on the various intervals the zeros create. A sign chart gives us an overall sense of the graph of the function, but without concerning ourselves with any specific values of the function besides the zeros. For a sample sign chart, see
+ When a polynomial
- What does it mean to say that a rational function has a hole
at a certain point, and what algebraic structure leads to such behavior?
-
- How do we determine where a rational function has zeros and where it has vertical asymptotes? -
-- What does a sign chart reveal about the behavior of a rational function and how do we develop a sign chart from a given formula? -
-
- Because any rational function is the ratio of two polynomial functions, it's natural to ask questions about rational functions similar to those we ask about polynomials. With polynomials, it is often helpful to know where the function's value is zero. In a rational function
- Connected to these questions, we want to understand both where a rational function's output value is zero, as well as where the function is undefined. In addition, from the behavior of simple rational power functions such as
hole
- Two important features of any rational function
- If the numerator of a fraction approaches
- Similarly, if the denominator of a fraction approaches
- These two behaviors show how the zeros and vertical asympototes of a rational function
- Consider the rational function
- It is helpful with any rational function to factor the numerator and denominator. We note that
- Knowing that
A plot of
Zooming in on
How the graph of
- We know from our algebraic work with the denominator,
- In the table, we see that both the numerator and denominator get closer and closer to
- Finally, we also note that
- In the situation where a rational function is undefined at a point but does not have a vertical asymptote there, we'll say that the graph of the function has a
- Let the limit of
.
-
- The key observations regarding zeros, vertical asymptotes, and holes in
- Let
-
- If
- If
- If
- Just like with polynomial functions, we can use sign charts to describe the behavior of rational functions. The only significant difference for their use in this context is that we not only must include all
- Construct a sign chart for the function
- First, we fully factor
- Thus, we have three different
- On the interval
- Using similar reasoning, we can complete the sign chart shown in
The sign chart for
A plot of
- In both the sign chart and the figure, we see that
- To find a formula for a rational function with certain properties, we can reason in ways that are similar to our work with polynomials. Since the rational function must have a polynomial expression in both the numerator and denominator, by thinking about where the numerator and denominator must be zero, we can often generate a formula whose graph will satisfy the desired properties. -
- -
- If a rational function
- For a rational function
- By writing a rational function's numerator in factored form, we can generate a sign chart for the function that takes into account all of the zeros and vertical asymptotes of the function, which are the only points where the function can possibly change sign. By testing
+ What does it mean to say that a rational function has a hole
at a certain point, and what algebraic structure leads to such behavior?
+
+ How do we determine where a rational function has zeros and where it has vertical asymptotes? +
++ What does a sign chart reveal about the behavior of a rational function and how do we develop a sign chart from a given formula? +
+
+ Because any rational function is the ratio of two polynomial functions, it's natural to ask questions about rational functions similar to those we ask about polynomials. With polynomials, it is often helpful to know where the function's value is zero. In a rational function
+ Connected to these questions, we want to understand both where a rational function's output value is zero, as well as where the function is undefined. In addition, from the behavior of simple rational power functions such as
hole
+ Two important features of any rational function
+ If the numerator of a fraction approaches
+ Similarly, if the denominator of a fraction approaches
+ These two behaviors show how the zeros and vertical asympototes of a rational function
+ Consider the rational function
+ It is helpful with any rational function to factor the numerator and denominator. We note that
+ Knowing that
A plot of
Zooming in on
How the graph of
+ We know from our algebraic work with the denominator,
+ In the table, we see that both the numerator and denominator get closer and closer to
+ Finally, we also note that
+ In the situation where a rational function is undefined at a point but does not have a vertical asymptote there, we'll say that the graph of the function has a
+ Let the limit of
.
+
+ The key observations regarding zeros, vertical asymptotes, and holes in
+ Let
+
+ If
+ If
+ If
+ Just like with polynomial functions, we can use sign charts to describe the behavior of rational functions. The only significant difference for their use in this context is that we not only must include all
+ Construct a sign chart for the function
+ First, we fully factor
+ Thus, we have three different
+ On the interval
+ Using similar reasoning, we can complete the sign chart shown in
The sign chart for
A plot of
+ In both the sign chart and the figure, we see that
+ To find a formula for a rational function with certain properties, we can reason in ways that are similar to our work with polynomials. Since the rational function must have a polynomial expression in both the numerator and denominator, by thinking about where the numerator and denominator must be zero, we can often generate a formula whose graph will satisfy the desired properties. +
+ +
+ If a rational function
+ For a rational function
+ By writing a rational function's numerator in factored form, we can generate a sign chart for the function that takes into account all of the zeros and vertical asymptotes of the function, which are the only points where the function can possibly change sign. By testing
- What is a rational function? -
-- How can we determine key information about a rational function from its algebraic structure? -
-- Why are rational functions important? -
-
- The average rate of change of a function on an interval always involves a ratio. Indeed, for a given function
- Ratios of polynomial functions arise in several different important circumstances. Sometimes we are interested in what happens when the denominator approaches
- The functions
- A function
- Like with polynomial functions, we are interested in such natural questions as -
- What is the long range behavior of a given rational function? -
-- What is the domain of a given rational function? -
-
- How can we determine where a given rational function's value is
- We begin by focusing on the long-range behavior of rational functions. It's important first to recall our earlier work with power functions of the form
- We summarize and generalize the results of
- Let
-
- if
- if
- if
- In both situations (a) and (b), the value of
- Because a rational function can be written in the form
- Let
- Determine the domain of the function
- To find the domain of any rational function, we need to determine where the denominator is zero. The best way to find these values exactly is to factor the denominator. Thus, we observe that
-
- We note that when it comes to determining the domain of a rational function, the numerator is irrelevant: all that matters is where the denominator is
- Rational functions arise naturally in the study of the average rate of change of a polynomial function, leading to expressions such as
-
- In
- What happens if we instead fix the volume of the container and ask about how surface area can be written as a function of a single variable? -
- -
- Suppose we want to construct a circular cylinder that holds
- Neglecting any scrap, the amount of material it takes to construct the container is its surface area, which we know to be
-
- A rational function is a function whose formula can be written as the ratio of two polynomial functions. For instance,
- Two aspects of rational functions are straightforward to determine for any rational function. Given
- if the degree of
- if the degree of
- and if the degree of
- Two reasons that rational functions are important are that they arise naturally when we consider the average rate of change on an interval whose length varies and when we consider problems that relate the volume and surface area of three-dimensional containers when one of those two quantities is constrained. -
-+ What is a rational function? +
++ How can we determine key information about a rational function from its algebraic structure? +
++ Why are rational functions important? +
+
+ The average rate of change of a function on an interval always involves a ratio. Indeed, for a given function
+ Ratios of polynomial functions arise in several different important circumstances. Sometimes we are interested in what happens when the denominator approaches
+ The functions
+ A function
+ Like with polynomial functions, we are interested in such natural questions as +
+ What is the long range behavior of a given rational function? +
++ What is the domain of a given rational function? +
+
+ How can we determine where a given rational function's value is
+ We begin by focusing on the long-range behavior of rational functions. It's important first to recall our earlier work with power functions of the form
+ We summarize and generalize the results of
+ Let
+
+ if
+ if
+ if
+ In both situations (a) and (b), the value of
+ Because a rational function can be written in the form
+ Let
+ Determine the domain of the function
+ To find the domain of any rational function, we need to determine where the denominator is zero. The best way to find these values exactly is to factor the denominator. Thus, we observe that
+
+ We note that when it comes to determining the domain of a rational function, the numerator is irrelevant: all that matters is where the denominator is
+ Rational functions arise naturally in the study of the average rate of change of a polynomial function, leading to expressions such as
+
+ In
+ What happens if we instead fix the volume of the container and ask about how surface area can be written as a function of a single variable? +
+ +
+ Suppose we want to construct a circular cylinder that holds
+ Neglecting any scrap, the amount of material it takes to construct the container is its surface area, which we know to be
+
+ A rational function is a function whose formula can be written as the ratio of two polynomial functions. For instance,
+ Two aspects of rational functions are straightforward to determine for any rational function. Given
+ if the degree of
+ if the degree of
+ and if the degree of
+ Two reasons that rational functions are important are that they arise naturally when we consider the average rate of change on an interval whose length varies and when we consider problems that relate the volume and surface area of three-dimensional containers when one of those two quantities is constrained. +
+- How can we use inverse trigonometric functions to determine missing angles in right triangles? -
-- What situations require us to use technology to evaluate inverse trigonometric functions? -
-
- In our earlier work in
- While the original trigonometric functions take a particular angle as input and provide an output that can be viewed as the ratio of two sides of a right triangle, the inverse trigonometric functions take an input that can be viewed as a ratio of two sides of a right triangle and produce the corresponding angle as output. Indeed, it's imperative to remember that statements such as
-
as the angle whose cosine is
.
-
- Like the trigonometric functions themselves, there are a handful of important values of the inverse trigonometric functions that we can determine exactly without the aid of a computer. For instance, we know from the unit circle (
- In addition, there are many other values at which we may wish to know the angle that results from an inverse trigonometric function. To determine such values, we use a computational device (such as Desmos) in order to evaluate the function. -
- -
- Consider the right triangle pictured in
A right triangle with one known leg and known hypotenuse.
-
- Because we know the hypotenuse and the side opposite
- We can now find the remaining leg's length and the remaining angle's measure. If we let
- Now that we have developed the (restricted) sine, cosine, and tangent functions and their respective inverses, in any setting in which we have a right triangle together with one side length and any one additional piece of information (another side length or a non-right angle measurement), we can determine all of the remaining pieces of the triangle. In the activities that follow, we explore these possibilities in a variety of different applied contexts. -
- -- -
- Anytime we know two side lengths in a right triangle, we can use one of the inverse trigonometric functions to determine the measure of one of the non-right angles. For instance, if we know the values of
- If we instead know the hypotenuse and one of the two legs, we can use either the arcsine or arccosine function accordingly. -
-Finding an angle from knowing the legs in a right triangle.
-
- For situations other than angles or ratios that involve the
is the exact value of the angle whose cosine is
+ How can we use inverse trigonometric functions to determine missing angles in right triangles? +
++ What situations require us to use technology to evaluate inverse trigonometric functions? +
+
+ In our earlier work in
+ While the original trigonometric functions take a particular angle as input and provide an output that can be viewed as the ratio of two sides of a right triangle, the inverse trigonometric functions take an input that can be viewed as a ratio of two sides of a right triangle and produce the corresponding angle as output. Indeed, it's imperative to remember that statements such as
+
as the angle whose cosine is
.
+
+ Like the trigonometric functions themselves, there are a handful of important values of the inverse trigonometric functions that we can determine exactly without the aid of a computer. For instance, we know from the unit circle (
+ In addition, there are many other values at which we may wish to know the angle that results from an inverse trigonometric function. To determine such values, we use a computational device (such as Desmos) in order to evaluate the function. +
+ +
+ Consider the right triangle pictured in
A right triangle with one known leg and known hypotenuse.
+
+ Because we know the hypotenuse and the side opposite
+ We can now find the remaining leg's length and the remaining angle's measure. If we let
+ Now that we have developed the (restricted) sine, cosine, and tangent functions and their respective inverses, in any setting in which we have a right triangle together with one side length and any one additional piece of information (another side length or a non-right angle measurement), we can determine all of the remaining pieces of the triangle. In the activities that follow, we explore these possibilities in a variety of different applied contexts. +
+ ++ +
+ Anytime we know two side lengths in a right triangle, we can use one of the inverse trigonometric functions to determine the measure of one of the non-right angles. For instance, if we know the values of
+ If we instead know the hypotenuse and one of the two legs, we can use either the arcsine or arccosine function accordingly. +
+Finding an angle from knowing the legs in a right triangle.
+
+ For situations other than angles or ratios that involve the
is the exact value of the angle whose cosine is
- Is it possible for a periodic function that fails the Horizontal Line Test to have an inverse? -
-- For the restricted cosine, sine, and tangent functions, how do we define the corresponding arccosine, arcsine, and arctangent functions? -
-- What are the key properties of the arccosine, arcsine, and arctangent functions? -
-- In our prior work with inverse functions, we have seen several important principles, including -
- A function
- A function
- When
- and
- say the exact same thing,
- but from two different perspectives.
-
- The trigonometric functions
- It's also important to understand why the issue of finding an angle in terms of a known value of a trigonometric function is important.
- Suppose we know the following information about a right triangle:
- one leg has length
- While the original trigonometric functions
- For the cosine function restricted to the domain
- Let
- Note particularly that the output of the arccosine function is an angle. In addition, recall that in the context of the unit circle, an angle measured in radians and the corresponding arc length along the unit circle are numerically equal. This is why we use the arc
in arccosine
: given a value
- We recall that for any function with an inverse function, the inverse function reverses the process of the original function. We know that
can be read as saying
. Changing perspective and writing the equivalent statement
, we read this statement as
. Just as
as
or
. Key properties of the arccosine function can be summarized as follows.
-
-
- The restricted cosine function,
- The domain of
- The arccosine function is always decreasing on its domain. -
-- At right, a plot of the restricted cosine function (in light blue) and its corresponding inverse, the arccosine function (in dark blue). -
-ADD ALT TEXT TO THIS IMAGE
- Just as the natural logarithm function allowed us to rewrite exponential equations in an equivalent way (for instance,
. Indeed, these relationships are reflected in the plot above, where we see that any point
- We can develop an inverse function for a restricted version of the sine function in a similar way. As with the cosine function, we need to choose an interval on which the sine function is always increasing or always decreasing in order to have the function pass the horizontal line test. The standard choice is the domain
- Let
- Finally, we develop an inverse function for a restricted version of the tangent function. We choose the domain
- Let
-
- Any function that fails the Horizontal Line Test cannot have an inverse function. However, for a periodic function that fails the horizontal line test, if we restrict the domain of the function to an interval with no repeated outputs, we then determine a related function that does, in fact, have an inverse function. By choosing such an interval carefully, it is possible for us to develop the inverse functions of the restricted cosine, sine, and tangent functions. -
-
- We choose to define the restricted cosine, sine, and tangent functions on the respective domains
-
- For any
- For any
- For any real number
- To discuss the properties of the three inverse trigonometric functions, we plot them on the same axes as their corresponding restricted trigonometric functions. When we do so, we use
- The domain of
The restricted cosine function (in light blue) and its inverse,
The restricted sine function (in light blue) and its inverse,
- The domain of
- The domain of
The restricted tangent function (in light blue) and its inverse,
+ Is it possible for a periodic function that fails the Horizontal Line Test to have an inverse? +
++ For the restricted cosine, sine, and tangent functions, how do we define the corresponding arccosine, arcsine, and arctangent functions? +
++ What are the key properties of the arccosine, arcsine, and arctangent functions? +
++ In our prior work with inverse functions, we have seen several important principles, including +
+ A function
+ A function
+ When
+ and
+ say the exact same thing,
+ but from two different perspectives.
+
+ The trigonometric functions
+ It's also important to understand why the issue of finding an angle in terms of a known value of a trigonometric function is important.
+ Suppose we know the following information about a right triangle:
+ one leg has length
+ While the original trigonometric functions
+ For the cosine function restricted to the domain
+ Let
+ Note particularly that the output of the arccosine function is an angle. In addition, recall that in the context of the unit circle, an angle measured in radians and the corresponding arc length along the unit circle are numerically equal. This is why we use the arc
in arccosine
: given a value
+ We recall that for any function with an inverse function, the inverse function reverses the process of the original function. We know that
can be read as saying
. Changing perspective and writing the equivalent statement
, we read this statement as
. Just as
as
or
. Key properties of the arccosine function can be summarized as follows.
+
+
+ The restricted cosine function,
+ The domain of
+ The arccosine function is always decreasing on its domain. +
++ At right, a plot of the restricted cosine function (in light blue) and its corresponding inverse, the arccosine function (in dark blue). +
+ADD ALT TEXT TO THIS IMAGE
+ Just as the natural logarithm function allowed us to rewrite exponential equations in an equivalent way (for instance,
. Indeed, these relationships are reflected in the plot above, where we see that any point
+ We can develop an inverse function for a restricted version of the sine function in a similar way. As with the cosine function, we need to choose an interval on which the sine function is always increasing or always decreasing in order to have the function pass the horizontal line test. The standard choice is the domain
+ Let
+ Finally, we develop an inverse function for a restricted version of the tangent function. We choose the domain
+ Let
+
+ Any function that fails the Horizontal Line Test cannot have an inverse function. However, for a periodic function that fails the horizontal line test, if we restrict the domain of the function to an interval with no repeated outputs, we then determine a related function that does, in fact, have an inverse function. By choosing such an interval carefully, it is possible for us to develop the inverse functions of the restricted cosine, sine, and tangent functions. +
+
+ We choose to define the restricted cosine, sine, and tangent functions on the respective domains
+
+ For any
+ For any
+ For any real number
+ To discuss the properties of the three inverse trigonometric functions, we plot them on the same axes as their corresponding restricted trigonometric functions. When we do so, we use
+ The domain of
The restricted cosine function (in light blue) and its inverse,
The restricted sine function (in light blue) and its inverse,
+ The domain of
+ The domain of
The restricted tangent function (in light blue) and its inverse,
- What are the other
- How do the graphs of the secant, cosecant, and cotangent functions behave and how do these graphs compare to the cosine, sine, and tangent functions' graphs? -
-- What is a trigonometric identity and why are identities important? -
-- The sine and cosine functions, originally defined in the context of a point traversing the unit circle, are also central in right triangle trigonometry. They enable us to find missing information in right triangles in a straightforward way when we know one of the non-right angles and one of the three sides of the triangle, or two of the sides where one is the hypotenuse. In addition, we defined the tangent function in terms of the sine and cosine functions, and the tangent function offers additional options for finding missing information in right triangles. We've also seen how the inverses of the restricted sine, cosine, and tangent functions enable us to find missing angles in a wide variety of settings involving right triangles. -
- -
- One of the powerful aspects of trigonometry is that the subject offers us the opportunity to view the same idea from many different perspectives. As one example, we have observed that the functions
- While almost every question involving trigonometry can be answered using the sine, cosine, and tangent functions, sometimes it is convenient to use three related functions that are connected to the other three possible arrangements of ratios of sides in right triangles. -
- --
- For any real number
- For any real number
- For any real number
- Note particularly that like the tangent function, the secant, cosecant, and cotangent are also defined completely in terms of the sine and cosine functions. In the context of a right triangle with an angle
-
A right triangle with angle
- With these three additional trigonometric functions, we now have expressions that address all six possible combinations of two sides of a right triangle in a ratio. -
- -
- Because the sine and cosine functions are used to define each of the other four trigonometric functions, it follows that we can translate information known about the other functions back to information about the sine and cosine functions. For example, if we know that in a certain triangle
- It's also often possible to view given information in the context of the unit circle. With the earlier given information that
A
- But we could also view
- Like the tangent function, the secant, cosecant, and cotangent functions are defined in terms of the sine and cosine functions, so we can determine the exact values of these functions at each of the special points on the unit circle. In addition, we can use our understanding of the unit circle and the properties of the sine and cosine functions to determine key properties of these other trigonometric functions. We begin by investigating the secant function. -
- -
- Using the fact that u
. At all other points, the value of the secant function is simply the reciprocal of the cosine function's value. Since
-
- In addition, we observe that as
- Plotting the data in the table along with the expected asymptotes and connecting the points intuitively, we see the graph of the secant function in
A plot of the secant function with special points that come from the unit circle, plus the cosine function (dotted, in light blue).
-
- We see from both the table and the graph that the secant function has period
- For the function
- its domain is the set of all real numbers except
- its range is the set of all real numbers
- its period is
- An identity is an equation that is true for all possible values of
- Trigonometric identities are simply identities that involve trigonometric functions. While there are a large number of such identities one can study, we choose to focus on those that turn out to be most useful in the study of calculus. The most important trigonometric identity is the fundamental trigonometric identity, - which is a trigonometric restatement of the Pythagorean Theorem. -
- -
- For any real number
- Identities are important because they enable us to view the same idea from multiple perspectives. For example, the fundamental trigonometric identity allows us to think of
- There are two related Pythagorean identities that involve the tangent, secant,
- cotangent, and cosecant functions, which we can derive from the fundamental trigonometric identity by dividing both sides by either
- In calculus, it is also beneficial to know a couple of other standard identities for sums of angles or double angles.
-
- For all real numbers
- For all real numbers
- For any real number
- For any real number
-
- The secant, cosecant, and cotangent functions are respectively defined as the reciprocals of the cosine, sine, and tangent functions. That is,
-
- The graph of the cotangent function is similar to the graph of the tangent function, except that it is decreasing on every interval on which it is defined and has vertical asymptotes wherever
- The graphs of the secant and cosecant functions are different from the cosine and sine functions' graphs in several ways, including that their range is the set of all real numbers
- A trigonometric identity is an equation involving trigonometric functions that is true for every value of the variable for which the trigonometric functions are defined. For instance,
+ What are the other
+ How do the graphs of the secant, cosecant, and cotangent functions behave and how do these graphs compare to the cosine, sine, and tangent functions' graphs? +
++ What is a trigonometric identity and why are identities important? +
++ The sine and cosine functions, originally defined in the context of a point traversing the unit circle, are also central in right triangle trigonometry. They enable us to find missing information in right triangles in a straightforward way when we know one of the non-right angles and one of the three sides of the triangle, or two of the sides where one is the hypotenuse. In addition, we defined the tangent function in terms of the sine and cosine functions, and the tangent function offers additional options for finding missing information in right triangles. We've also seen how the inverses of the restricted sine, cosine, and tangent functions enable us to find missing angles in a wide variety of settings involving right triangles. +
+ +
+ One of the powerful aspects of trigonometry is that the subject offers us the opportunity to view the same idea from many different perspectives. As one example, we have observed that the functions
+ While almost every question involving trigonometry can be answered using the sine, cosine, and tangent functions, sometimes it is convenient to use three related functions that are connected to the other three possible arrangements of ratios of sides in right triangles. +
+ ++
+ For any real number
+ For any real number
+ For any real number
+ Note particularly that like the tangent function, the secant, cosecant, and cotangent are also defined completely in terms of the sine and cosine functions. In the context of a right triangle with an angle
+
A right triangle with angle
+ With these three additional trigonometric functions, we now have expressions that address all six possible combinations of two sides of a right triangle in a ratio. +
+ +
+ Because the sine and cosine functions are used to define each of the other four trigonometric functions, it follows that we can translate information known about the other functions back to information about the sine and cosine functions. For example, if we know that in a certain triangle
+ It's also often possible to view given information in the context of the unit circle. With the earlier given information that
A
+ But we could also view
+ Like the tangent function, the secant, cosecant, and cotangent functions are defined in terms of the sine and cosine functions, so we can determine the exact values of these functions at each of the special points on the unit circle. In addition, we can use our understanding of the unit circle and the properties of the sine and cosine functions to determine key properties of these other trigonometric functions. We begin by investigating the secant function. +
+ +
+ Using the fact that u
. At all other points, the value of the secant function is simply the reciprocal of the cosine function's value. Since
+
+ In addition, we observe that as
+ Plotting the data in the table along with the expected asymptotes and connecting the points intuitively, we see the graph of the secant function in
A plot of the secant function with special points that come from the unit circle, plus the cosine function (dotted, in light blue).
+
+ We see from both the table and the graph that the secant function has period
+ For the function
+ its domain is the set of all real numbers except
+ its range is the set of all real numbers
+ its period is
+ An identity is an equation that is true for all possible values of
+ Trigonometric identities are simply identities that involve trigonometric functions. While there are a large number of such identities one can study, we choose to focus on those that turn out to be most useful in the study of calculus. The most important trigonometric identity is the fundamental trigonometric identity, + which is a trigonometric restatement of the Pythagorean Theorem. +
+ +
+ For any real number
+ Identities are important because they enable us to view the same idea from multiple perspectives. For example, the fundamental trigonometric identity allows us to think of
+ There are two related Pythagorean identities that involve the tangent, secant,
+ cotangent, and cosecant functions, which we can derive from the fundamental trigonometric identity by dividing both sides by either
+ In calculus, it is also beneficial to know a couple of other standard identities for sums of angles or double angles.
+
+ For all real numbers
+ For all real numbers
+ For any real number
+ For any real number
+
+ The secant, cosecant, and cotangent functions are respectively defined as the reciprocals of the cosine, sine, and tangent functions. That is,
+
+ The graph of the cotangent function is similar to the graph of the tangent function, except that it is decreasing on every interval on which it is defined and has vertical asymptotes wherever
+ The graphs of the secant and cosecant functions are different from the cosine and sine functions' graphs in several ways, including that their range is the set of all real numbers
+ A trigonometric identity is an equation involving trigonometric functions that is true for every value of the variable for which the trigonometric functions are defined. For instance,
- How can we view
- Why can both
- What is the minimum amount of information we need about a right triangle in order to completely determine all of its sides and angles? -
-
- In
- By changing our perspective slightly, we can see that it is equivalent to think of the values of the sine and cosine function as representing the lengths of legs in right triangles. Specifically, given a central angle
The values of
The values of
- This right triangle perspective enables us to use the sine and cosine functions to determine missing information in certain right triangles. The field of mathematics that studies relationships among the angles and sides of triangles is called trigonometry.
- In the study of functions, linear functions are the simplest of all and form a foundation for our understanding of functions that have other shapes. In the study of geometric shapes (polygons, circles, and more), the simplest figure of all is the triangle, and understanding triangles is foundational to understanding many other geometric ideas. To begin, we list some familiar and important facts about triangles. -
- --
- Any triangle has
- In any triangle in the Cartesian plane, the sum of the measures of the interior angles is
- In any triangle in the plane, knowing three of the six features of a triangle is often enough information to determine the missing three features.
- The situation is especially nice for right triangles, because then we only have five unknown features since one of the angles is
The
- Because we know the values of the cosine and sine functions from the unit circle, right triangles with hypotentuse
- A right triangle with a hypotenuse of length
The roles of
- From the similar triangles in
- In a right triangle where one of the non-right angles is adj
denotes the length of the leg adjacent to opp
the length the side opposite hyp
the length of the hypotenuse,
-
ADD ALT TEXT TO THIS IMAGE
- In
- In any right triangle, -
- --
- if we know one of the non-right angles and the length of the hypotenuse, we can find both the remaining non-right angle and the lengths of the two legs; -
-- if we know the length of two sides of the triangle, then we can find the length of the other side; -
-- if we know the measure of one non-right angle, then we can find the measure of the remaining angle. -
-
- In scenario (1.), all
- We will revisit scenario (2) in our future work. Now, however, we want to consider a situation that is similar to (1), but where it is one leg of the triangle instead of the hypotenuse that is known. We encountered this in
- Consider a right triangle in which one of the non-right angles is
- Determine (both exactly and approximately) the measures of all of the remaining sides and angles in the triangle. -
-The given right triangle.
-
- From the fact that
- Solving
-
- In a right triangle with hypotenuse
- Because a right triangle with hypotenuse of length
- In a right triangle, there are five additional characteristics: the measures of the two non-right angles and the lengths of the three sides. In general, if we know one of those two angles and one of the three sides, we can determine all of the remaining pieces. -
-
+ How can we view
+ Why can both
+ What is the minimum amount of information we need about a right triangle in order to completely determine all of its sides and angles? +
+
+ In
+ By changing our perspective slightly, we can see that it is equivalent to think of the values of the sine and cosine function as representing the lengths of legs in right triangles. Specifically, given a central angle
The values of
The values of
+ This right triangle perspective enables us to use the sine and cosine functions to determine missing information in certain right triangles. The field of mathematics that studies relationships among the angles and sides of triangles is called trigonometry.
+ In the study of functions, linear functions are the simplest of all and form a foundation for our understanding of functions that have other shapes. In the study of geometric shapes (polygons, circles, and more), the simplest figure of all is the triangle, and understanding triangles is foundational to understanding many other geometric ideas. To begin, we list some familiar and important facts about triangles. +
+ ++
+ Any triangle has
+ In any triangle in the Cartesian plane, the sum of the measures of the interior angles is
+ In any triangle in the plane, knowing three of the six features of a triangle is often enough information to determine the missing three features.
+ The situation is especially nice for right triangles, because then we only have five unknown features since one of the angles is
The
+ Because we know the values of the cosine and sine functions from the unit circle, right triangles with hypotentuse
+ A right triangle with a hypotenuse of length
The roles of
+ From the similar triangles in
+ In a right triangle where one of the non-right angles is adj
denotes the length of the leg adjacent to opp
the length the side opposite hyp
the length of the hypotenuse,
+
ADD ALT TEXT TO THIS IMAGE
+ In
+ In any right triangle, +
+ ++
+ if we know one of the non-right angles and the length of the hypotenuse, we can find both the remaining non-right angle and the lengths of the two legs; +
++ if we know the length of two sides of the triangle, then we can find the length of the other side; +
++ if we know the measure of one non-right angle, then we can find the measure of the remaining angle. +
+
+ In scenario (1.), all
+ We will revisit scenario (2) in our future work. Now, however, we want to consider a situation that is similar to (1), but where it is one leg of the triangle instead of the hypotenuse that is known. We encountered this in
+ Consider a right triangle in which one of the non-right angles is
+ Determine (both exactly and approximately) the measures of all of the remaining sides and angles in the triangle. +
+The given right triangle.
+
+ From the fact that
+ Solving
+
+ In a right triangle with hypotenuse
+ Because a right triangle with hypotenuse of length
+ In a right triangle, there are five additional characteristics: the measures of the two non-right angles and the lengths of the three sides. In general, if we know one of those two angles and one of the three sides, we can determine all of the remaining pieces. +
+- How is the tangent function defined in terms of the sine and cosine functions? -
-- Why is the graph of the tangent function so different from the graphs of the sine and cosine functions? -
-- What are important applications of the tangent function? -
-
- In
Finding the width of the river.
-- It turns out that we regularly need to evaluate the ratio of the sine and cosine functions at the same angle, so it is convenient to define a new function to be their ratio. -
- -
- For any real number
An angle
A right triangle with legs adjacent and opposite angle
- Because the tangent function is defined in terms of the two fundamental circular functions by the rule
- From the viewpoint of hyp
and legs
- adj
and opp
that are respectively adjacent and opposite the known angle
- We typically use the first perspective of tracking the ratio of the
- Because the tangent function is defined in terms of the sine and cosine functions, its values and behavior are completely determined by those two functions. To begin, we know the value of u
.
-
-
- In addition, we observe that as
- Plotting the data in the table along with the expected asymptotes and connecting the points intuitively, we see the graph of the tangent function in
A plot of the tangent function together with special points that come from the unit circle.
-
- We see from
- For the function
- its domain is the set of all real numbers except
- its range is the set of all real numbers; -
-
- its period is
- is increasing on any interval on which the function is defined at every point in the interval. -
-- While the tangent function is an interesting mathematical function for its own sake, its most important applications arise in the setting of right triangles, and for the remainder of this section we will focus on that perspective. -
- -- The tangent function offers us an additional choice when working in right triangles with limited information. In the setting where we have a right triangle with one additional known angle, if we know the length of the hypotenuse, we can use either the sine or cosine of the angle to help us easily find the remaining side lengths. But in the setting where we know only the length of one leg, the tangent function now allows us to determine the value of the remaining leg in a similarly straightforward way, and from there the hypotenuse. -
- -
- Use the tangent function to determine the width,
A right triangle with one angle and one leg known.
-
- Using the perspective that
- Once we know the river's width, we can use the Pythagorean theorem or the sine function to determine the distance from
- The tangent function finds a wide range of applications in finding missing information in right triangles where information about one or more legs of the triangle is known. -
- --
- The tangent function is defined defined to be the ratio of the sine and cosine functions according to the rule
-
- The graph of the tangent function differs substantially from the graphs of the sine and cosine functions, primarily because near values where
- The tangent function finds some of its most important applications in the setting of right triangles where one leg of the triangle is known and one of the non-right angles is known. Computing the tangent of the known angle, say
+ How is the tangent function defined in terms of the sine and cosine functions? +
++ Why is the graph of the tangent function so different from the graphs of the sine and cosine functions? +
++ What are important applications of the tangent function? +
+
+ In
Finding the width of the river.
++ It turns out that we regularly need to evaluate the ratio of the sine and cosine functions at the same angle, so it is convenient to define a new function to be their ratio. +
+ +
+ For any real number
An angle
A right triangle with legs adjacent and opposite angle
+ Because the tangent function is defined in terms of the two fundamental circular functions by the rule
+ From the viewpoint of hyp
and legs
+ adj
and opp
that are respectively adjacent and opposite the known angle
+ We typically use the first perspective of tracking the ratio of the
+ Because the tangent function is defined in terms of the sine and cosine functions, its values and behavior are completely determined by those two functions. To begin, we know the value of u
.
+
+
+ In addition, we observe that as
+ Plotting the data in the table along with the expected asymptotes and connecting the points intuitively, we see the graph of the tangent function in
A plot of the tangent function together with special points that come from the unit circle.
+
+ We see from
+ For the function
+ its domain is the set of all real numbers except
+ its range is the set of all real numbers; +
+
+ its period is
+ is increasing on any interval on which the function is defined at every point in the interval. +
++ While the tangent function is an interesting mathematical function for its own sake, its most important applications arise in the setting of right triangles, and for the remainder of this section we will focus on that perspective. +
+ ++ The tangent function offers us an additional choice when working in right triangles with limited information. In the setting where we have a right triangle with one additional known angle, if we know the length of the hypotenuse, we can use either the sine or cosine of the angle to help us easily find the remaining side lengths. But in the setting where we know only the length of one leg, the tangent function now allows us to determine the value of the remaining leg in a similarly straightforward way, and from there the hypotenuse. +
+ +
+ Use the tangent function to determine the width,
A right triangle with one angle and one leg known.
+
+ Using the perspective that
+ Once we know the river's width, we can use the Pythagorean theorem or the sine function to determine the distance from
+ The tangent function finds a wide range of applications in finding missing information in right triangles where information about one or more legs of the triangle is known. +
+ ++
+ The tangent function is defined defined to be the ratio of the sine and cosine functions according to the rule
+
+ The graph of the tangent function differs substantially from the graphs of the sine and cosine functions, primarily because near values where
+ The tangent function finds some of its most important applications in the setting of right triangles where one leg of the triangle is known and one of the non-right angles is known. Computing the tangent of the known angle, say
+ Any graph passing through
Since
+ Any graph passing through
Since
+ These conditions are impossible to satisfy simultaneously. +
These conditions are impossible to satisfy simultaneously. Given
+ For Kent County,
For Kent County, the population in 1990 was 500,631 and in 2010 was 602,622, so @@ -105,7 +108,9 @@
+ The units are people per year for both. +
The units on In an average year between 1990 and 2010, the population of Ottawa County was
+ In an average year between 1990 and 2010, the population of Ottawa County was increasing by approximately 3801.65 people per year. +
- Between 1990 and 2010, the population of Ottawa County grew by an average of - approximately 3801.65 people per year. + In an average year between 1990 and 2010, the population of Ottawa County was increasing by approximately 3801.65 people per year.
+ Kent County had a greater average rate of change during the time interval
For Kent County on
Using the most recent decade's rate of change as a guide, Ottawa County grew at @@ -167,11 +176,5 @@
+
Computing the function values:
+
Computing function values:
+ (a)
+
+ (b)
+ On the graph of
+ False. +
+
False. Although
Answers will vary but will be linear.
Any linear function has constant average rate of change. For example, @@ -134,11 +161,5 @@
See solutions to individual tasks above.
-The circle is not a function of
The circle is not a function of
- The curve in the righthand figure is a function of
+ The relationship between the day of the year and the S&P500 stock index is a function. +
The closing value of the S&P500 can be expressed as a function of the day of @@ -73,7 +75,9 @@
+ The odometer reading cannot be viewed as a function of the car's velocity. +
The odometer reading cannot be viewed as a function of the car's velocity.
@@ -134,7 +138,9 @@
+ Not a function, because there is at least one input value which corresponds to more than one output value.
+
The table does not represent a function, because the input values
@@ -142,11 +148,5 @@
+ At
At
The domain of each model is
The domain of each model is determined by the time it takes the tank to drain. @@ -73,7 +81,12 @@
+ When the tank is full, there are
When the tank is full, the depth of the water equals the diameter of the tank, @@ -97,7 +110,10 @@
+ Descriptions will vary. The graph of
The graph of
+ The model's domain is restricted to
The model
+ The height function should be linear and decreasing. The formula is
+
The height function should be linear and decreasing, because the height decreases
by the same amount (
Since depth can't be negative and can't exceed the tank's diameter of
The domain is
The domain of
+
Neither claim is valid.
Neither claim is valid. The domain of
No, the tank cannot hold 300 cubic meters of water.
No. The maximum value of
Volume, height, surface area, and time are changing. Rate of water entering, height of tank, and radius of tank are not changing.
Changing: volume, height, surface area, and time. Not changing: rate of water entering, height of tank, and radius of tank.
Quantities that are changing include the volume of water in the tank, the height of the water, the surface area of the top of the water, and time. Quantities that are not changing include the rate at which water enters, the height of the tank, and the radius of the tank.
Sketches should show a sphere with labeled radius
Answers will vary. A sketch should show a sphere with labeled radius
Changing: volume, height, surface area, and time. Not changing: rate of water being pumped out and radius of the tank.
Quantities that are changing include the volume of water in the tank, the height of the water, the surface area of the top of the water, and time. Quantities that are not changing include the rate at which water is pumped out and the radius of the tank.
Since the radius is
Approximately
Water is removed at
A graph of volume versus time, using the values from the table. The graph is a straight line through the origin with slope
Since water is removed at a constant rate,
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
Blank axes for making a graph of height versus time.
Blank axes for making a graph of height versus time.
Sketches should show an S-shaped decreasing curve from
When
See solutions to individual tasks above.
-Sketches should show a sphere with labeled radius
Sketches should look something like the following image.
+An sphere with labeled radius
Answers will vary. A sketch should show a sphere with labeled radius
An sphere with labeled radius
ADD ALT TEXT TO THIS IMAGE
Blank axes for graphing volume versus time.
A graph of volume versus time, using the values from the table. The graph is a straight line through the origin with slope
A graph of volume versus time, using the values from the table. The graph is a straight line through
Since water is removed at a constant rate,
A graph of volume versus time, using the values from the table. The graph is a straight line through
Since
Since
+ The function
The function ADD ALT TEXT TO THIS IMAGE Plot of
+ The graph is a line segment from ADD ALT TEXT TO THIS IMAGE Blank axes for plotting Plot of
+ The graph is a line segment from Plot of the function
+ The graph is a line segment from Both Dolbear's function Plot of
+ The graph is a line segment from Plot of the function
+ The graph is a line segment from
The domain of
As an abstract mathematical function, both the domain and range are all real @@ -92,11 +244,5 @@
See solutions to individual tasks above.
-ADD ALT TEXT TO THIS IMAGE
graph of two piecewise linear functions
+ The first piece of
The first piece of
@@ -70,7 +74,7 @@
From the graph,
From the graph,
From the graph,
From the table,
From the table,
From the table,
We need
We need
Using the points
+ The slope has units of
The slope
Setting
A reasonable domain is
A reasonable domain is
The main context of the sequence of questions in this activity comes from Exercise 30 on p.
The slope is
Solving The function appears to be linear because the rate of change is constant per
The function appears to be linear because the rate of change is constant:
@@ -134,12 +134,12 @@
ADD ALT TEXT TO THIS IMAGE Graph of a function
The graph has slope
-
+ The slope is
The slope is
+ The water level rises at a constant rate of
Since
The slope is
Using the standard model
A graph of
Plotting
A graph of
- From the graph, the balloon appears to land at approximately
Setting
The vertex occurs at
A graph of
Using
A graph of
If
If
With
With
With
With
The parameter
The parameter
Yes. Since
One,
Three points determine a unique quadratic, so exactly one such function exists. @@ -44,7 +44,7 @@
Two, because the vertex is below the
We can guarantee exactly two
Yes. Using vertex form
Two, because the vertex
The vertex
Zero, because
The discriminant is
Consider the functions
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
A piecewise linear function
A piecewise function
From the graphs,
From the graphs,
- From the graphs,
Yes:
@@ -33,7 +33,11 @@
+ At a speed of 60 miles per hour, the car consumes 0.04 gallons of fuel + for each mile traveled. +
+At a speed of 60 miles per hour, the car consumes 0.04 gallons of fuel @@ -51,7 +55,12 @@
+
+
+ All three convey information about the fuel consumption at
All three convey information about fuel consumption at 60 mph, but with @@ -108,7 +126,12 @@
+
@@ -36,7 +36,14 @@
+
For
The parabola that is valid for
The left-side parabola
For
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
Blank axes for graphing
A piecewise linear function
A piecewise function
The graph of
The graph of
A piecewise function
Reading from the graph of
See solutions to individual tasks above.
-graph of two piecewise linear functions
graph of two piecewise linear functions
The first piece of
The first piece of
diff --git a/source/activities/act-changing-inverse-Dolbear.xml b/source/activities/act-changing-inverse-Dolbear.xml index 73c10604..1c73f31e 100755 --- a/source/activities/act-changing-inverse-Dolbear.xml +++ b/source/activities/act-changing-inverse-Dolbear.xml @@ -26,7 +26,7 @@
Subtracting 40 and multiplying by 4: @@ -41,7 +41,7 @@
The function
The function
They express the same relationship between
They express the same relationship between
The function
The function The function
The function The function
The function The function
The function
- The functions Graph of a decreasing function Graph of a piecewise linear function ADD ALT TEXT TO THIS IMAGE The function
The function
Using
Graph of
The range of
At the endpoints:
Graph of
Setting
No. Setting
No. Setting
Consider the functions
Graph of a piecewise linear function
Graph of a function
ADD ALT TEXT TO THIS IMAGE
Shift right 1 unit, then compress vertically by a factor of
Graph of the piecewise linear function
The function
The function
Graph of the piecewise linear function
The function
Shift left
Graph of the function
The function
The function
The function
Graph of the function
The function
The function
Both shift
Algebraically: @@ -92,26 +128,35 @@
Find a formula for a function
Graph of a function
Graph of a function
Graph of a function
@@ -20,11 +20,27 @@
ADD ALT TEXT TO THIS IMAGE A parent function ADD ALT TEXT TO THIS IMAGE A parent function
- On the same axes as the plot of
The function
A parent function
The graph of
A parent function
The function
A parent function
The graph of
A parent function
+ The function
Substituting
Consider the functions
ADD ALT TEXT TO THIS IMAGE
A parent function
ADD ALT TEXT TO THIS IMAGE
A parent function
- On the same axes as the plot of
+ The graph of
A parent function
The graph of
A parent function
+ The graph of
A parent function
The graph of
A parent function
- On the additional copies of the two figures below, sketch the graphs of the following transformed functions:
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
A parent function
A parent function
A parent function
A parent function
- For
A parent function
A parent function
+ The function
The function
A vertical translation,
A vertical translation,
A horizontal translation,
A horizontal translation,
The parent function
The parent function
The parent function
The parent function
- Continuing, we now consider the function
The function
The function
The function
The function
- Finally, we arrive at
diff --git a/xsl/apc-activity-workbook.xsl b/xsl/apc-activity-workbook.xsl
index 4096e122..8eab3da3 100644
--- a/xsl/apc-activity-workbook.xsl
+++ b/xsl/apc-activity-workbook.xsl
@@ -18,7 +18,7 @@
%entities;
]>
- Answer the following questions exactly wherever possible. If you estimate a value, do so to at least
- The
- Using
- The
-
- The
-
- The value of
- If
- The value of
- Using
- The average rate of change of
-
- The average rate of change of
-
+ Answer the following questions exactly wherever possible. If you estimate a value, do so to at least
+ The
+ Using
+ The
+
+ The
+
+
+ The value of
+ If
+ The value of
+ Using
+ The average rate of change of
+
+
+ The average rate of change of
+
+
The function
The function
The function
The function
The average rate of change of
+ The most rapid average rates of change on both graphs occur near the zero crossing points (where the function crosses the midline). +
+The most rapid average rates of change on both graphs occur near the zero crossing points (where the function crosses the midline). @@ -114,18 +118,12 @@
quadrants II and III
The function
@@ -26,7 +26,11 @@
+
ADD ALT TEXT TO THIS IMAGE
Blank axes for graphing
a plot of
a plot of
+
+
+ The graphs of
- The graphs of
@@ -20,11 +20,25 @@
ADD ALT TEXT TO THIS IMAGE Circle centered at Blank axes for plotting ADD ALT TEXT TO THIS IMAGE
1 unit apart
+The eight points on the circle are evenly spaced, and the circle has a circumference of 8 units. Thus, the distance between any two sequential points is 1 unit. @@ -50,7 +65,8 @@
The
The point
The completed table is:
@@ -221,9 +264,24 @@
Graph of Graph of
+ This graph is shifted up, shifted to the right, and is compressed horizontally compared to the textbook figure. +
+The graph has a very similar shape to Figure 2.1.5. This graph is shifted up, shifted to the right, and is compressed horizontally compared to the textbook figure. @@ -247,18 +308,14 @@
To find
+
+ The weight slows down as it reaches the farthest distance away from the midline and speeds up back toward the center. The greatest (steepest) negative rates of change occur near the midline where the function is decreasing, in intervals such as
The greatest (steepest) negative rates of change occur near the midline where the function is decreasing. Examples include intervals such as
+ Examples of longest such intervals are
The function is decreasing from each peak to each trough. Examples of longest such intervals are
+ The intervals on which
The intervals on which
The weight is moving toward the wall but slowing down.
On intervals that are decreasing and concave up, the weight is moving toward the wall, but at a decreasing rate (slowing down). @@ -253,18 +275,16 @@
+ At the highest and lowest points, the function has the smallest rates of change. Near the midline, the function has its greatest rates of change. +
+At the highest and lowest points, the function has the smallest rates of change. Near the midline, the function has its greatest rates of change.
+ The period of the motion is
The period of the motion is
+ The greatest displacement of the weight is
- The greatest displacement of the weight is equal to the maximum of the graph: 13 inches. The least displacement is the minimum: 3 inches. The range of
+
+
+ The average rate of change of this function represents the speed of the weight. Taken together, these two values indicate that the weight is moving more slowly on the interval
The average rate of change
The value of
In a circle of radius 11, the arc length intercepted by a central angle of
In a circle of radius 3, the central angle that intercepts an arc length
The radius is
The angle corresponding to the arc length is
+
-
+
-
+
-
+
-
+
-
+
Because a
+ The resulting shape forms an equilateral triangle where all three interior angles are
When the
When a
+ The coordinates of the point at
The coordinates of the point at
@@ -20,11 +20,21 @@
ADD ALT TEXT TO THIS IMAGE A parent function ADD ALT TEXT TO THIS IMAGE A parent function
+ The function
Graphs of two horizontal scaling functions of
The function
Graphs of two horizontal scaling functions of
+ The function
Graphs of two horizontal scaling functions of
The function
Graphs of two horizontal scaling functions of
ADD ALT TEXT TO THIS IMAGE
ADD ALT TEXT TO THIS IMAGE
A parent function
A parent function
+ The function
Graphs of transformations which scale both horizontally and vertically.
The function
Graphs of transformations which scale both horizontally and vertically.
The function
The function
+ The midline is
Graph of
@@ -37,7 +43,7 @@ d(t) = 1.25\cos\!\left(\frac{2\pi}{3}(t - 1.25)\right) + 2.75.
-Graph of
One formula is
diff --git a/source/activities/act-circular-sinusoidal-period.xml b/source/activities/act-circular-sinusoidal-period.xml index 1536a356..4469f660 100755 --- a/source/activities/act-circular-sinusoidal-period.xml +++ b/source/activities/act-circular-sinusoidal-period.xml @@ -26,7 +26,11 @@
+ Period
Period
+ Period
Period
+ Period 8, amplitude 2, midline
Period 8, amplitude 2, midline
+ Period 4, amplitude 2, midline
Period 4, amplitude 2, midline
+ Note that
Note that
@@ -26,7 +26,7 @@
All real numbers, or
The domain of
- Allowing for all possible values of
The
When
- When
+ When
- When
ADD ALT TEXT TO THIS IMAGE
Graph of two exponential functions,
We can tell that
- The function
- Long-term trends, unbounded behavior, and limits. By working to study functions as objects themselves, we often focus on trends and overall behavior. In addition to introducing the ideas of a function being increasing or decreasing, or concave up or concave down, we also focus on using algebraic approaces to comprehend function behavior where the input and/or output increase without bound. In anticipation of calculus, we use limit notation and work to understand how this shorthand summarizes key features of functions. + Long-term trends, unbounded behavior, and limits. By working to study functions as objects themselves, we often focus on trends and overall behavior. In addition to introducing the ideas of a function being increasing or decreasing, or concave up or concave down, we also focus on using algebraic approaches to comprehend function behavior where the input and/or output increase without bound. In anticipation of calculus, we use limit notation and work to understand how this shorthand summarizes key features of functions.
When
When
When
Graph of two exponential functions,
- The value of an automobile is depreciating. When the car is
Exactly:
- Given
- Using the exponential model determined in (a), determine the purchase value of the car and then use Desmos to estimate when the car will be worth less than $
The purchase value of the car is approximately
- Using the approximate model, the purchase value of the car is approximately $
- Suppose instead that the car's value is modeled by a linear function
If the car's value is linear, then
+ The exponential model seems more realistic because new cars decrease in value faster rate at the beginning and more slowly as they get older. +
+- The exponential model seems more realistic because new cars decrease in value at a faster rate than older cars. + The exponential model seems more realistic because new cars decrease in value faster rate at the beginning and more slowly as they get older.
@@ -23,15 +23,31 @@
A function
+ Any line with negative slope, for example,
A line with negative slope
- If
A line with negative slope
+ For example,
The function
If
The function
- A function
+ One option is a downward-opening parabola, such as
A downward-opening parabola which has its peak at
+ One option is a downward-opening parabola, such as
A downward-opening parabola which has its peak at
+ For example,
The function
- Let
The function
- A function
+ For example,
The function
+ We want to take the previous example and flip it left to right, or across the
The function
+ The function
- The function
+ The function
- The function
+ The function
The function
+ The function
The function
+ The function
The function
+ The function
The function
- A potato initially at room temperature (
+
The numerical value of
+ The expression
- The long-range behavior of
- The value of
Check your work above by plotting the function
ADD ALT TEXT TO THIS IMAGE
Blank axes for plotting
+ The function
Graph of
- The function
Graph of
+ We can view
We can view
@@ -35,12 +35,19 @@
+ The graph of
graph of
The graph of
graph of
+ The function
graph of
The function
graph of
ADD ALT TEXT TO THIS IMAGE
Blank axes for plotting
+ Since
graph of
Since
graph of
+ The temperature of the refrigerator is
Because
+
+
- The function
+ As
As The function
+ The statement makes sense because the rate of change on small intervals near
The statement makes sense because the rate of change on small intervals near
+ The value of
The value of
+
- For
- For
- The equation
- The equation
- The equation
- The equation
+
+
+
+
+
-
+
-
+
-
+
-
+ There is no solution because the equation gives
There is no solution because the equation gives
From
- From
- From
From
From
From
@@ -26,7 +26,11 @@
+ The domain of
The domain of
+ The domain of
The domain of
+ For every real number
For every real number
+ For every positive real number
For every positive real number
Complete the following tables with both exact and approximate values of
ADD ALT TEXT TO THIS IMAGE
Blank axes for graphing
graphs of
graphs of
+ Both
Both
+ The function
The function
+ The function
The function
+ Experimenting with Desmos, the exponential model
Experimenting with Desmos, the exponential model
From
From
From
From
+ Since the soda cools toward the refrigerator temperature in the long run, and
Finally, using
- Since the soda cools toward the refrigerator temperature in the long run, and
Finally, using
Setting
+ Using
Using
If
ADD ALT TEXT TO THIS IMAGE
Blank axes for graphing
+ A typical graph of
graph of
A typical graph of
graph of
+ The population appears to grow most rapidly at the midpoint of the transition from near
The population appears to grow most rapidly at the midpoint of the transition from near
As
+
Since
+
Since
+ The average rates of change are:
+
Using
Setting
This appendix contains answers to all activities in the text. Answers for preview activities are not included.
From 2aa20d3742e1c4dfcd68b646f01a673ce9c75096 Mon Sep 17 00:00:00 2001 From: Chrissy Safranski
+ Throwing to first base. The angle the throw makes with the first base line is
+ Throwing to second base. The angle with the first base line is
Place home plate at the origin, first base at
- Throwing to first base. The straight-line distance is
Throwing to second base. The displacement from
+ The hypotenuse has length
- The hypotenuse has length
Since
Since
+ For general height
+ The average rates of change are:
diff --git a/source/activities/act-trig-finding-angles-roof.xml b/source/activities/act-trig-finding-angles-roof.xml index 04e6c615..51e53858 100755 --- a/source/activities/act-trig-finding-angles-roof.xml +++ b/source/activities/act-trig-finding-angles-roof.xml @@ -25,11 +25,13 @@
+ The angle of the roof with the horizontal is
- The angle of the roof with the horizontal is
The domain of
The domain of
ADD ALT TEXT TO THIS IMAGE
Blank axes for plotting the graph of sine and arcsine.
Graph of
Graph of
False. Since
False. Since
+ The domain of the arctangent function is all real numbers
The domain of the arctangent function is all real numbers
+
ADD ALT TEXT TO THIS IMAGE
A graph of tangent for sketching the graph of arctangent.
graph of tangent and arctangent
graph of tangent and arctangent
+ As
As
+
Using the sum identity:
+
Substituting into the average rate of change: @@ -87,18 +99,16 @@
+ As
As
+ Since
- Since
+ The cotangent function is positive in quadrants I and III and negative in quadrants II and IV. +
+The cotangent function is positive in quadrants I and III (where sine and cosine have the same sign) and negative in quadrants II and IV (where they have opposite signs). @@ -331,7 +339,11 @@
+ At every integer multiple of
The cotangent function has vertical asymptotes wherever
+ The domain of the cotangent function is all real numbers except integer multiples of
The domain of the cotangent function is all real numbers except integer multiples of
ADD ALT TEXT TO THIS IMAGE
Axes with tangent for graphing cotangent
graph of cotangent
graph of cotangent
+ The cotangent function is always decreasing on every interval where it is defined. +
+The cotangent function is always decreasing on every interval where it is defined. @@ -389,7 +411,7 @@
The period of the cotangent function is
The graph of
- The graph of
ADD ALT TEXT TO THIS IMAGE
Axes for plotting
+ The cosecant values are reciprocals of sine. In Q1 and Q2:
- The csc values are reciprocals of sin: Q1-Q2:
The cosecant function is positive in quadrants I and II and negative in quadrants III and IV.
Since
At every integer multiple of
The cosecant function has vertical asymptotes wherever
+ The domain of the cosecant function is all real numbers except integer multiples of
The domain of the cosecant function is all real numbers except integer multiples of
graph of cosecant
graph of cosecant
The period of the cosecant function is
+
+ If
+ With hypotenuse
- With hypotenuse
Without a specific side length, we can only determine that the triangle is similar to a 3-4-5 right triangle: sides are
- We know
+ With angle
With angle
+ With hypotenuse
- With hypotenuse
+ With legs
- With legs
+ With angle
- With angle
ADD ALT TEXT TO THIS IMAGE
Two right triangles which share vertex
+ Both triangles share the angle
Both triangles share the angle
+ The ratio
The ratio
In the smaller right triangle
Since
ADD ALT TEXT TO THIS IMAGE
A triangle
The river is approximately
The river is
ADD ALT TEXT TO THIS IMAGE
Triangle with various lengths and angles labeled
Using the right triangle with the
Using the right triangle with the
From (a),
The exact value is
Using
approximately
If the initial measurements were taken from
The cables have to be about
The cables have to be
ADD ALT TEXT TO THIS IMAGE
Two supertall skyscrapers a width of
The two towers have to be
+ Two trends to observe: (1) As
Two trends to observe: (1) As
+ On
On
+ Two trends to observe: (1) The graphs with even
Two trends to observe: (1) The graphs with even
+ On
On
+ Two trends: (1) For even-L-shaped
near
Two trends: (1) For even-L-shaped
near
+ On
On
+ On
On
+ Two trends with the wider window: (1) The graphs with even exponents are symmetric about the
Two trends with the wider window: (1) The graphs with even exponents are symmetric about the
+ As
As
About
The polynomial
The polynomial
About
The polynomial
The polynomial
About
The polynomial
The polynomial
Each additional term in the polynomial extends the range of
Each additional term in the polynomial extends the range of
Following the pattern of alternating signs and even powers, the next polynomials are
+
Following the pattern of alternating signs and even powers, the next polynomials are
-
ADD ALT TEXT TO THIS IMAGE
Image of a three-dimensional rectangular box
Suppose that we want to ship a parcel that has a square end of width
The square end has side length
The square end has side length
The girth is the perimeter of the square end:
Solving for
The volume of the rectangular box with square end of side
We need both
- With a square end of side
The surface area of a closed cylinder is
Solving for
Substituting into
We need
- The surface area constraint
One example:
One example:
No such polynomial exists.
No such polynomial exists. A degree-4 polynomial has even degree, so both limits as
One example:
One example:
No such polynomial exists.
No such polynomial exists. A degree-5 polynomial with odd degree and a positive leading coefficient has
One formula:
- One formula:
ADD ALT TEXT TO THIS IMAGE
Graph of a polynomial
One example is:
- From the graph (reading off the zeros and their behavior), one example with
A polynomial
ADD ALT TEXT TO THIS IMAGE
Sign chart showing roots of
One example:
- From the sign chart (positive, then negative, then positive, then negative, with the pattern showing even-multiplicity zeros where sign doesn't change and odd-multiplicity zeros where it does), one example:
Not possible.
It is not possible to have a degree 9 polynomial satisfying the sign chart from part (c) and
Not possible.
It is not possible to have a degree-11 polynomial matching the graph in part (b) if that graph shows the same long-term behavior at both ends. A degree-11 polynomial has odd degree, so its limits at
The degree is
always positive
The factor
The real zeros are
The real zeros are
From left to right around the roots: positive, negative, negative, positive
The constant
+ The graph is positive (above the
The graph is positive (above the
+ Using a graphing utility, the zeros at
Using a graphing utility, the zeros at
The box has a shorter base side of length
The box has a shorter base side of length
The volume is
The volume is
The open box (no top) has: one rectangular base (
Substituting
From a graph of
From a graph of
- With base sides
The domain of
The denominator
The domain of
Factoring the denominator:
The domain of
Each fraction is undefined when its denominator is zero:
The domain of
The denominator is zero when
The domain of
Factoring the denominator:
The domain of
The denominator is zero when
- Rational functions are undefined wherever the denominator is zero. Factor each denominator and exclude those
+
Domain: all reals except
Zeros:
Vertical asymptote:
Hole: at
Horizontal asymptote: none
Factor:
+
Domain: all reals except
Zero:
Vertical asymptote:
Holes: none
Horizontal asymptote:
The numerator
+
Domain: all reals except
Zero:
Vertical asymptote:
Hole: at
Horizontal asymptote:
Factor:
+
Domain: all reals except
Zeros:
Vertical asymptotes: none
Hole: at
Horizontal asymptote:
Factor:
+
Domain: all reals except
Zeros:
Vertical asymptotes:
Hole: at
Horizontal asymptote:
The factor
+
Domain: all real numbers.
Zeros: none.
Vertical asymptotes: none.
Holes: none.
Horizontal asymptote:
The numerator is always
- Factor numerator and denominator, cancel common factors, then identify: zeros (numerator zero in reduced form), vertical asymptotes (denominator zero in reduced form), holes (cancelled factors), horizontal asymptote (degree comparison of leading terms). -
-One such function is
+
We need: a factor
One such function is
+
We need: exactly one factor
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Graph of a function with vertical asymptotes at
One formula consistent with these features is
+
From the graph,
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Sign chart showing roots of
One formula is
+
From the sign chart, the function has zeros at
One formula is
+
We need: two factors that cancel for the holes; two denominator factors that don't cancel for the VAs; two remaining numerator factors for the zeros; and equal numerator/denominator degree for the HA. One formula is
-
- Sample answers: (a)
Multiplying numerator and denominator by
Having rewritten
As
Next, determine
-
For the same reason, as
The graph of
The graph of
- Multiplying by
Using a similar algebraic approach to our work in
As
Multiplying
The graph of
The graph of
Next, use appropriate algebraic work to consider
As
Multiplying
The graph of
The graph of
- For
Consider the function
Reading from the graph of
Reading from the graph of
During a major rainstorm, the rainfall at Gerald R. Ford Airport is measured on a frequent basis for a
Recall from
In a new Desmos worksheet, let
Adjust your definition of
Determine the exact values of
Consider the polynomial function given by
-
As
Multiplying
Recall that for any function
Explain why your work in (a) and (b) together with some algebra shows that
-
In calculus, we move from average rate of change to instantaneous rate of change by letting
Read the graph of
Similarly, read the graph of
With formulas for
In the Ironman Triathlon,
competitors swim
The triathlete exits the water after the swim at
The bike finishes at
Key points: exits water at
See graphs below.
The triathlete exits the water after the swim at
The bike finishes at
Key points: exits water at
See graphs below.
diff --git a/source/exercises/ez-exp-log-properties.xml b/source/exercises/ez-exp-log-properties.xml index 7f494d23..09f7d962 100755 --- a/source/exercises/ez-exp-log-properties.xml +++ b/source/exercises/ez-exp-log-properties.xml @@ -155,9 +155,9 @@
We solve
Recall that
@@ -259,9 +259,9 @@
We solve
Solving
Let
It turns out that the problem of determining the amount of salt in the tank at time
The trough has two equilateral triangular ends and two rectangular side panels (the open top means there is no rectangular top panel). The surface area is
-
Setting the surface area equal to
Let the box have width
Substituting into the surface area formula:
-
Consider the polynomial function given by
-
@@ -84,9 +84,9 @@
Now consider the related but different polynomial
-
We need: numerator degree greater than denominator degree (no horizontal asymptote); zeros at
Zeros only at
Reading from the graph: zeros near
Substituting:
-
With
If
Each side panel is a
For the function
A water balloon is tossed vertically from a fifth story window. Its height,
Write
Later in this section, we'll learn that one model for how a population grows over time can be given by a function of the form
-
After cutting
The average cost per gram to produce
Dividing both terms in the numerator of
For a function
For a function
The average rate of change of a function on an interval gives us an excellent way to describe how the function behaves, on average. For instance, if we compute
Finally, we can even use the average rate of change of a function to predict future behavior. Since the population was changing on average by
It is helpful be able to connect information about a function's average rate of change and its graph. For instance, if we have determined that
For a function
It is often helpful to look at a function's formula and observe algebraic structure. For instance, given the quadratic function
-
Solution. Observe that the units on shares
and the units on dollars per share
. Thus when we compute the product
- dollars
, which is the total value of held stock. Hence,
-
The absolute value of a real number, denoted by
A piecewise function is a function whose formula consists of at least two different formulas in such a way that which formula applies depends on where the input falls in the domain. For example, given two functions
If
The Celsius and Fahrenheit temperature scales are connected by a linear function. Indeed, the function that converts Fahrenheit to Celsius is
-
Recall that the average rate of change of a function
To think about the interval
By definition, we know that
-
In
Because the expression
We start with the abstract function
Sometimes it is possible to use variables and one or more equations to connect quantities that are changing in tandem. In the aquarium example from the preview activity, we can observe that the volume,
If we consider the conical tank discussed in
Note that at any time while the tank is being filled,
diff --git a/source/sec-changing-inverse.xml b/source/sec-changing-inverse.xml
index 70d27bd3..f79a135e 100755
--- a/source/sec-changing-inverse.xml
+++ b/source/sec-changing-inverse.xml
@@ -60,9 +60,9 @@
Let
When a given function has an inverse function, it allows us to express the same relationship from two different points of view. For instance, if
If
Do the functions
Taking
We attempt similar reasoning for the second function,
A function
Let's suppose we know that a function
Solution. Using
A line with slope
Visualizing the various components of point-slope form is important. For a line through
For the line with slope
Like with the Dolbear function, it is often useful to write a linear function (whose output is called
Let
While the quadratic formula will always provide any real solutions to
We first observe that we can write
Next, observe that the vertex of
For an object tossed vertically from an initial height of
Recall that we considered a water balloon tossed vertically from a fifth story window whose height,
For an object with height
From an algebraic point of view, horizontal translations are slightly more complicated than vertical ones. Given
While there are some transformations that can be executed in either order (such as a combination of a horizontal translation and a vertical translation, as seen in part (b) of
Given a central angle in the unit circle that measures
Given a central angle in the unit circle that measures
In particular, since the sine graph can be viewed as the cosine graph shifted
For any real number
Given real numbers
We can also understand this from the perspective of function composition. To evaluate
For any constant
Given real numbers
Given any circular periodic function for which the midline, amplitude, period, and an anchor point are known, we can find a corresponding formula for the function of the form
-
Remembering that
First, in
The differences in certain average rates of change appear to become more extreme if we consider shorter arcs along the circle. Next we consider traveling
If we pick any point
To study the circular functions generated by the unit circle, we will also animate a point and let it traverse the circle. Starting at
If a central angle measuring
@@ -184,9 +184,9 @@
In any circle of radius
In
: we could similarly write any function
The number
If we compare the graphs and some selected outputs of each function, as in
By the rules of exponents, we can rewrite this last equation equivalently as
-
Suppose that a certain mutual fund has a
If we repeat our computations for the second year, we observe that
-
Let
In contrast, the function
An additional trend is apparent in the graphs in
Let
Because positive integer exponents are a shorthand way to express repeated multiplication, we can use the multiplication rule for logarithms to think about exponents as well. For example,
-
For any positive real number
Since the model has form
To determine how long it takes for the population to reach
There are three fundamental rules for exponents given nonzero base
Logarithms are very important in determining values that arise in equations of the form
-
We can think of the natural logarithm, base-
. For instance,
- the power to which we raise
; the latter equation is true since when we raise
. The key relationships between the natural exponential and the natural logarithm function are investigated in
In
The natural logarithm often enables us to solve an equation that involves
. We know that it is equivalent to say
-
In addition, we make a key observation about the use of exponents. For the function
The data in the bottom row of
We have also begun to see the important role that logarithms play in work with exponential models. The natural logarithm is the inverse of the natural exponential function and satisfies the important rule that
If we assume that a population grows at a rate that is proportionate to the size of the population, it follows that the population grows exponentially according to the model
-
Because the exponential function
In
symbol to represent a quantity that gets larger and larger with no bound on its growth.
Let
If the value of
@@ -114,9 +114,9 @@
We use limit notation in related, natural ways to express patterns we see in function behavior. For instance, we write
In the situation where the power
The notation
-
Similarly, the notation
-
Polynomial functions are the simplest of all functions in mathematics in part because they only involve multiplication and addition. In any applied setting where we can formulate key ideas using only those arithmetic operations, it's natural that polynomial functions model the corresponding phenomena. For example, in
A different use of polynomial functions arises with Bezier curves.
The main issue to realize is that the form of the curve depends on a special family of cubic polynomials:
-
Polynomials arise naturally in the study of problems involving the volume and surface area of three-dimensional containers such as boxes and cylinders because these formulas fundamentally involve sums and products of variables. For instance, the volume of a cylinder is
Polynomial functions can be used to approximate non-polynomial curves and functions in many different ways. One example is found in cubic Bezier curves which use a collection of control points to enable the user to manipulate curves to pass through select points in such a way that the curve first travels in a certain direction. Another example is in the remarkable approximation of non-polynomial functions like the sine function, as given by
-
Indeed, if we instead view linear functions as having form
-
Given real numbers
The Zero Product Property
- If the function is in standard form, say
- If the function is in factored form, say
- When a polynomial
If the numerator of a fraction approaches
Similarly, if the denominator of a fraction approaches
These two behaviors show how the zeros and vertical asympototes of a rational function
In the situation where a rational function is undefined at a point but does not have a vertical asymptote there, we'll say that the graph of the function has a
Let the limit of
.
If
First, we fully factor
Thus, we have three different
On the interval
@@ -299,9 +299,9 @@
If a rational function
The average rate of change of a function on an interval always involves a ratio. Indeed, for a given function
A function
We begin by focusing on the long-range behavior of rational functions. It's important first to recall our earlier work with power functions of the form
if
if
if
To find the domain of any rational function, we need to determine where the denominator is zero. The best way to find these values exactly is to factor the denominator. Thus, we observe that
-
Rational functions arise naturally in the study of the average rate of change of a polynomial function, leading to expressions such as
-
In
Neglecting any scrap, the amount of material it takes to construct the container is its surface area, which we know to be
-
While the original trigonometric functions take a particular angle as input and provide an output that can be viewed as the ratio of two sides of a right triangle, the inverse trigonometric functions take an input that can be viewed as a ratio of two sides of a right triangle and produce the corresponding angle as output. Indeed, it's imperative to remember that statements such as
-
as the angle whose cosine is
.
We can now find the remaining leg's length and the remaining angle's measure. If we let
Anytime we know two side lengths in a right triangle, we can use one of the inverse trigonometric functions to determine the measure of one of the non-right angles. For instance, if we know the values of
diff --git a/source/sec-trig-inverse.xml b/source/sec-trig-inverse.xml
index b3e5d5f9..8997e3a7 100755
--- a/source/sec-trig-inverse.xml
+++ b/source/sec-trig-inverse.xml
@@ -75,9 +75,9 @@
and thus these functions on their full domains do not have inverse functions.
At the same time, it is reasonable to think about changing perspective and viewing angles as outputs in certain restricted settings.
For instance, we may want to say both
-
Let
We recall that for any function with an inverse function, the inverse function reverses the process of the original function. We know that
can be read as saying
. Changing perspective and writing the equivalent statement
, we read this statement as
. Just as
as
or
. Key properties of the arccosine function can be summarized as follows.
Let
Let
For any real number
For any real number
For any real number
An identity is an equation that is true for all possible values of
There are two related Pythagorean identities that involve the tangent, secant,
cotangent, and cosecant functions, which we can derive from the fundamental trigonometric identity by dividing both sides by either
@@ -369,9 +369,9 @@
The secant, cosecant, and cotangent functions are respectively defined as the reciprocals of the cosine, sine, and tangent functions. That is,
-
In a right triangle where one of the non-right angles is adj
denotes the length of the leg adjacent to opp
the length the side opposite hyp
the length of the hypotenuse,
-
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Because a right triangle with hypotenuse of length
In
For any real number
From the viewpoint of hyp
and legs
adj
and opp
that are respectively adjacent and opposite the known angle
@@ -116,9 +116,9 @@
Because the tangent function is defined in terms of the sine and cosine functions, its values and behavior are completely determined by those two functions. To begin, we know the value of u
.
In addition, we observe that as
Using the perspective that
@@ -342,9 +342,9 @@
The tangent function is defined defined to be the ratio of the sine and cosine functions according to the rule
-
The tangent function finds some of its most important applications in the setting of right triangles where one leg of the triangle is known and one of the non-right angles is known. Computing the tangent of the known angle, say