What is the inverse cosine function in the math library for C/C++?? i looked in the header and all it had was cos, cosh, and acos… but none of them seem to be the inverse function.

acos == arccos. I guess the developers of the stdlib were too lazy to write it out in full

Ooo, that makes me feel old… the differnece between arc and inv is just a question of age!

Lol, thanks, but what is cosh then?

hyperbolic cosine

cosh(x) = (e^x + e^-x) / 2