Applying the divergence theorem to find total surface charge

[Physgeek64]

Homework Statement

Sorry- I've figured it out, but I am afraid I don't know how to delete the thread.

Thank you though :)

Homework Equations

Below

The Attempt at a Solution

Photo below- I promise its coming! I've started by using cylindrical coordinates, but I wasn't sure if spherical coordinates would be better? Ill attach my photo below, but I'm stuck as to where to go from here. Many thanks in advance, I promise the photo is coming- I just don't know how to attach it on this section

 

[Physgeek64]

My working