> there are at least four different competing methods, all with subtle tradeoffs. As is the case with most implementations of things, even elementary things, t

> there are at least four different competing methods, all with subtle tradeoffs. As is the case with most implementations of things, even elementary things, that have to do with the real numbers on discrete hardware (see numerical integration, square roots and inverses, trig functions, various approximations of the real numbers themselves, etc.). Real numbers are hard. It's a blessing only a minority of computer programs need to actually deal with them (or their approximations).