DATA: While cleaning out old files I ran across some various old cheat-sheets and primers for some of my college math classes, mostly pre-calc stuff. They can come in handy when you want to model something like, oh... I dunno, the temperature of your house or the forthcoming economic collapse.
Definition of a Derivative
Limits and Continuity
Natural Logs and e
They may be owned by one of my old TA's or some book, so don't go telling on me. ;)