Primitive of Square of Sine of a x over Cosine of a x

Theorem

 * $\displaystyle \int \frac {\sin^2 a x \rd x} {\cos a x} = \frac {-\sin a x} a + \frac 1 a \ln \size {\map \tan {\frac \pi 4 + \frac {a x} 2} } + C$

Also see

 * Primitive of $\dfrac {\cos^2 a x} {\sin a x}$