I don't know how to text in the limits but the interior are and , and the exterior are 0 and 2.
What do I do with this please?
While what ChiSigma said is correct, it's only valid to separate the variables if the variables can be separated, as they can be in this case. A better way in my opinion, is to perform the innermost integration of the ENTIRE function, then the outer integration of the entire function. This will work in ALL cases.