You've got atan2, cos, exp, log, sin, and sqrt, all in the core distribution. To perform exponentiation, use x ** y. If you don't want to roll your own complex numbers, you can check out Math::Complex. For the missing trig functions, you can easily make functions (e.g., tan(x)=sin(x)/cos(x), etc.) to do it.

For more complete modules, you might want to tryMath::Taylor or Math::Calculus::TaylorSeries.