Add info from the docstring for random.gammavariate() to the docs.
diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index f0c4add..31cb945 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -163,6 +163,7 @@
The end-point value ``b`` may or may not be included in the range
depending on floating-point rounding in the equation ``a + (b-a) * random()``.
+
.. function:: triangular(low, high, mode)
Return a random floating point number *N* such that ``low <= N <= high`` and
@@ -191,6 +192,12 @@
Gamma distribution. (*Not* the gamma function!) 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
+
.. function:: gauss(mu, sigma)