Proving the Hypervolume of a Hypersphere using a Quadruple Integral

The assignment is to prove the hypervolume of a hypersphere with a quadruple integral using trigonometric substitutions and integral formulas (given) to confirm/prove the the hypervolume of a hypersphere. The hypervolume equation is given as ((pi^2)(a^4))/2. The assignment has more detailed information and reference material.

We did a similar activity in class, but as I have never attempted a quadruple integral I wanted to be able to have a solution to compare my work to for the hypersphere. Thanks!