Primitive of Power of x over Power of x squared plus a squared

Theorem

 * $\displaystyle \int \frac {x^m \ \mathrm d x} {\left({x^2 + a^2}\right)^n} = \int \frac {x^{m - 2} \ \mathrm d x} {\left({x^2 + a^2}\right)^{n-1} } - a^2 \int \frac {x^{m - 2} \ \mathrm d x} {\left({x^2 + a^2}\right)^n}$