Documentation for routine atan assembled from the following pages:

Class: Cool §

From Cool

(Cool) routine atan §

Defined as:

sub atan(Numeric(Cool))
method atan()

Coerces the invocant (or in sub form, the argument) to Numeric, and returns its arc-tangent in radians.

say atan(3);                # OUTPUT: «1.24904577239825␤» 
say 3.atan;                 # OUTPUT: «1.24904577239825␤»