sympy/sympy — pull request #1152 by manoj2378 (2012-03-21 00:39:31+00:00)
Title: Improved trigonometric Functions

Patch Status:
evaluates sin(log(x)) interms of x.Similarly for cos,tan,cot functions
Gives sin(sinh(x)).rewrite(exp) in terms of exp(x) only.
Gives sin(sinh(x)).rewrite(exp).subs(x, sinh(h)) in terms of exp(sinh(x))
Similar results for cos,tan,cot functions.
Added tests.All passed.

Present Status :
calling sin(log(x)) gives sin(log(x)).
gives sin(sinh(x)) in terms of exp(sinh(x)) but not in exp(x) which is expected by user.
gives sin(sinh(x)).rewrite(exp).subs(x, sinh(x)) gives in terms of exp(sinh(x)).