• NAME
• SYNOPSIS
• DESCRIPTION

NAME

cos - cosine function

SYNOPSIS

cos EXPR

cos

DESCRIPTION

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] ) }