Primitive of Reciprocal of x by Root of Power of x minus Power of a

Theorem

 * $\displaystyle \int \frac {\mathrm d x} {x \sqrt {x^n - a^n} } = \frac 2 {n \sqrt {a^n} } \arccos \sqrt {\frac {a^n} {x^n} }$

Proof
Now: