Primitive of Power of Cosine of a x by Sine of a x

Theorem

 * $\displaystyle \int \cos^n a x \sin a x \ \mathrm d x = \frac {-\cos^{n + 1} a x} {\left({n + 1}\right) a} + C$

Also see

 * Primitive of $\sin^n a x \cos a x$