9 Geeky Equations You Should (at Least Pretend to) Know

Somewhat sad aside, I once saw a guy in a park wearing a T-shirt that had the equations "F / A", "sqrt(-1)", and "PV / NR" written on it (spelling MIT with some relatively trivial manipulation).

I asked him where he got it, because I thought it was clever, and he said he got it from MIT where he went to school, but he didn't know any of the equations (and, by extension, what the shirt actually said) because he majored in architecture.

Previous discussion: http://news.ycombinator.com/item?id=3196555