Havin' a bad headache!

Didn't really sleep well lately n still havin' a bad headache. Slept at 4am last nite finishin' up some codes 2 show Prof Yow today. Prof Sluzek who is collaboratin' wif me is finishin' up his part too, meetin' me on Wed. We r at war! I wanna submit a few proposals 2 the top conf this year, which is due in Dec. Last nite was kinda writin' n fixin' some bugs in the code. How to calculate the angle bet 2 vectors? E.g. using dot product:

A.B = A B cosine(theta),
where theta = inverse cosine(dot product/(magnitude of Vector 1 X magnitude of Vector 2)) and A and B are normalized to Unit vectors.

There r so much equations 2 to be added 2 the papers too, i can't afford 2 make any mistake!!