Here's my version of a double post. I asked this same question a couple of years ago, but we now have a bunch of new members, so I thought I'd give it another go.
I read somewhere that Laplace's equation is separable in 11 different (presumably orthogonal) coordinate systems. Obviously there is Cartesian, cylindrical, and spherical-polar. Does anyone know of other coordinate systems? Thanks!
Dang it all! How did you do that? I tried every variation on a search that I could think of and got nowhere. When I looked up conical coordinates the bottom of the Wikipedia page had the whole darned list.
I stink at web searches. (sigh)
Thanks for the info!
Wolfram MathWorld: The Web's Most Extensive Mathematics Resource and typed in Laplace's equation
and got this
Laplace's Equation -- from Wolfram MathWorld