Double Integration in Polar and its Applications

Just another couple of pennies to keep you interested. The Gaussian integral for a cartesian coordinate system can be derived/solved (sorry don't know which is the correct word) by changing from cartesian to polar coordinates, and invoking a very nice equality of product of integrals. Once you understand how it works, you will never need to flip to the data book to find out whether to put your constants below or on top of or with 2pi.

Hadriel