And the reason for this (that so far as I can tell no one has yet said) is simple: those functions are defined for all values of their argument. tan isn't. arcsin and arccos aren't.
Well, division isn't defined for all values of its arguments either, and neither are log and sqrt. So, I agree it's not much of a reason at all.
in reply to Re^2: Perl oddities
in thread Perl oddities