Primitive of Square of Cosine of a x

Theorem

 * $\displaystyle \int \cos^2 a x \ \mathrm d x = \frac x 2 + \frac {\sin 2 a x} {4 a} + C$

Also see

 * Primitive of $\sin^2 a x$
 * Primitive of $\tan^2 a x$
 * Primitive of $\cot^2 a x$
 * Primitive of $\sec^2 a x$
 * Primitive of $\csc^2 a x$