Primitive of Reciprocal of p plus q by Sine of a x/Weierstrass Substitution

Lemma for Primitive of Reciprocal of $p + q \sin a x$
The Weierstrass Substitution of $\displaystyle \int \frac {\mathrm d x} {p + q \sin a x}$ is:
 * $\displaystyle \frac 2 a \int \frac {\mathrm d u} {p u^2 + 2 q u + p}$

where $u = \tan \dfrac {a x} 2$.