Hmm, we have the sin and cos functions, I think it's not too hard knowing the formulae to come up with the correct calculation.
Expressions like AAAtri look obscure and probably would make a lot of people just go "wtf". I think cubic interpolation is about the most complex math that should be built in, otherwise there's no knowing where to stop (plus interpolation is used loads in games). We could go on with integrals, differentiation, statistical analysis etc. but I think that ought to go in a plugin rather than the runtime.