[racket] SU(2) and friends

I meant to get back to this earlier.  You might want to look at

Geometry of Representation Spaces in SU(2) - advanced, but with some real gems
http://arxiv.org/pdf/1001.2408

The Quaternions and the Spaces S3, SU(2), SO(3), and RP3
http://www.cis.upenn.edu/~cis610/cis610sl7.pdf

The first of these is fairly advanced, but if you have a background in differential geometry, it's well worth reading. The second is more accessible, using explicit matrix manipulations and such.

Oh, and don't forget Wolfram Mathworld! It's a very useful online encyclopedia of mathematics.

http://mathworld.wolfram.com/SpecialUnitaryGroup.html