-- Perl 5.8.7 documentation --
cos
Perl functions A-Z | Perl functions by category | The 'perlfunc' manpage
  • cos EXPR
  • cos

    Returns the cosine of EXPR (expressed in radians). If EXPR is omitted, takes cosine of $_ .

    For the inverse cosine operation, you may use the Math::Trig::acos() function, or use this relation:

        sub acos { atan2( sqrt(1 - $_[0] * $_[0]), $_[0] ) }