Primitive of x squared by Arccosine of x over a

Theorem

 * $\displaystyle \int x^2 \arccos \frac x a \ \mathrm d x = \frac {x^3} 3 \arccos \frac x a - \frac {\left({x^2 + 2 a^2}\right) \sqrt {a^2 - x^2} } 9 + C$

Proof
With a view to expressing the primitive in the form:
 * $\displaystyle \int u \frac {\mathrm d v}{\mathrm d x} \ \mathrm d x = u v - \int v \frac {\mathrm d u}{\mathrm d x} \ \mathrm d x$

let:

and let:

Then:

Also see

 * Primitive of $x^2 \arcsin \dfrac x a$