sympy/sympy — pull request #1502 by zanzibar7 (2012-08-21 22:53:19+00:00)
Title: Improve trig evaluation

This is an updated version of the code I posted in relation to
issue 2949. http://code.google.com/p/sympy/issues/detail?id=2949

In can produce exact radical expressions for n pi/12 and other values,
and can be extended to calculate any sin or cos that has an exact
representation in terms of nested square roots by adding a few more
partial-fraction decompositions.

This is my first attempt at contributing code. Feedback welcome.