Chapter 14.3, Problem 42ES

Use polar coordinates to find the volume of the solid that is above the $xy-\text{plane,}$ inside the cylinder the cylinder $x^2+y^2-ay=0,$ and inside the ellipsoid $\frac{x^2}{a^2}+\frac{y^2}{a^2}+\frac{z^2}{c^2}=1$