http://www.perlmonks.org?node_id=900247


in reply to Re: OT: ASA formula
in thread OT: ASA formula

There is of course also Math::Trig (in fact the POSIX entry for tan() also references this).

It also is part of Perl's core distribution, but if your administrator has been doing things to the distribution (which might account for your error), then all bets are off.