diff --git a/doc/equations/polygamma3.mml b/doc/equations/polygamma3.mml
index 3568763aa4..08430ae38a 100644
--- a/doc/equations/polygamma3.mml
+++ b/doc/equations/polygamma3.mml
@@ -86,7 +86,7 @@
π
- n
+ x
diff --git a/doc/equations/polygamma3.svg b/doc/equations/polygamma3.svg
index 3e05baaefd..c635a04d29 100644
--- a/doc/equations/polygamma3.svg
+++ b/doc/equations/polygamma3.svg
@@ -1,2 +1,2 @@
-∂ncot(πx)∂xn=πnsinn+1(πx)∑k=0n−1Ck,ncosk(πn)
\ No newline at end of file
+∂ncot(πx)∂xn=πnsinn+1(πx)∑k=0n−1Ck,ncosk(πx)
\ No newline at end of file
diff --git a/doc/equations/polygamma7.mml b/doc/equations/polygamma7.mml
index d3ea70c853..696abaa9b5 100644
--- a/doc/equations/polygamma7.mml
+++ b/doc/equations/polygamma7.mml
@@ -13,7 +13,7 @@
∂
∂
- x
+ θ
@@ -73,7 +73,7 @@
cos
- n
+ k
+
1
@@ -88,7 +88,7 @@
cos
- n
+ k
−
1
diff --git a/doc/equations/polygamma7.svg b/doc/equations/polygamma7.svg
index 2f83cc0b43..711404dd01 100644
--- a/doc/equations/polygamma7.svg
+++ b/doc/equations/polygamma7.svg
@@ -1,2 +1,2 @@
-∂∂xcosk(θ)sinn(θ)=1sinn+1(θ)((k−n)cosn+1(θ)−kcosn−1(θ))
\ No newline at end of file
+∂∂θcosk(θ)sinn(θ)=1sinn+1(θ)((k−n)cosk+1(θ)−kcosk−1(θ))
\ No newline at end of file
diff --git a/doc/sf/polygamma.qbk b/doc/sf/polygamma.qbk
index 1e5e0eabfb..7500d4beb3 100644
--- a/doc/sf/polygamma.qbk
+++ b/doc/sf/polygamma.qbk
@@ -66,7 +66,7 @@ has the general form:
[equation polygamma3]
The coefficients of the cosine terms can be calculated iteratively starting
-from ['C[sub 1,0] = -1] and then using
+from ['C[sub 0,1] = -1] and then using
[equation polygamma7]