add headings
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 594ee92..1eb2d71 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -21,8 +21,9 @@
The following functions are provided by this module. Except when explicitly
noted otherwise, all return values are floats.
-Number-theoretic and representation functions:
+Number-theoretic and representation functions
+---------------------------------------------
.. function:: ceil(x)
@@ -146,7 +147,9 @@
platform C double type), in which case any float *x* with ``abs(x) >= 2**52``
necessarily has no fractional bits.
-Power and logarithmic functions:
+
+Power and logarithmic functions
+-------------------------------
.. function:: exp(x)
@@ -193,7 +196,8 @@
Return the square root of *x*.
-Trigonometric functions:
+Trigonometric functions
+-----------------------
.. function:: acos(x)
@@ -241,7 +245,8 @@
Return the tangent of *x* radians.
-Angular conversion:
+Angular conversion
+------------------
.. function:: degrees(x)
@@ -253,7 +258,8 @@
Converts angle *x* from degrees to radians.
-Hyperbolic functions:
+Hyperbolic functions
+--------------------
.. function:: acosh(x)
@@ -291,7 +297,8 @@
Return the hyperbolic tangent of *x*.
-The module also defines two mathematical constants:
+Constants
+---------
.. data:: pi