Surface Integral of a Cylindrical Surface

[Iamblu]

Homework Statement

What is the integral of the function x^2z taken over the entire surface of
a right circular cylinder of height h which stands on the circle x^2 + y^2 = a^2

Homework Equations

The Attempt at a Solution

My problem is writing the equation in cylindrical form if that makes any sense. Do I just use the equation of the circle?

 

[Quinzio]

You have to write a double integral in polar form.
You may find useful to remember that: $r^2 = x^2+y^2$ and $x = r\ \cos \theta$