# Find the volume of the solid bound by {eq}z = 4 - (x^2 + y^2) {/eq} and z = 0.

## Question:

Find the volume of the solid bound by {eq}z = 4 - (x^2 + y^2) {/eq} and z = 0.

## Cylindrical Coordinates:

Recall that we can find the volume of region by setting up and evaluating a triple integral. Since our region possesses axial symmetry, we will find it convenient to use cylindrical coordinates. Recall

{eq}x = r \cos \theta {/eq}

{eq}y = r \sin \theta {/eq}

{eq}z = z {/eq}

{eq}r^2 = x^2+y^2 {/eq}

{eq}\theta = \tan^{-1} \frac{y}{x} {/eq}

{eq}dV = r \ dz \ dr \ d\theta {/eq}