Issue 10787: Document the probability density function for random.gammavariate.
diff --git a/Lib/random.py b/Lib/random.py
index 01e1420..dcc79d1 100644
--- a/Lib/random.py
+++ b/Lib/random.py
@@ -490,6 +490,12 @@
Conditions on the parameters are alpha > 0 and beta > 0.
+ The probability distribution function is:
+
+ x ** (alpha - 1) * math.exp(-x / beta)
+ pdf(x) = --------------------------------------
+ math.gamma(alpha) * beta ** alpha
+
"""
# alpha > 0, beta > 0, mean is alpha*beta, variance is alpha*beta**2