10.2.24 Simplifying and expressing preferentially with cosines
Any trigonometric function can be written in terms of sines and
cosines, and even powers of sines can be turned into powers of cosines by
using the identity sin(x)2+cos(x)2=1. The
trigcos command performs these substitutions.
- trigcos takes
expr, an expression containing trigonometric functions.
- trigsin(expr) returns expr
with the trigonometric functions rewritten in terms of sines and
cosines, with as many sines as possible transformed to cosines.
Example
| trigcos(sin(x)^4+cos(x)^2+1) |