## cos function - calculate the cosine value

**cos function** calculates the cosine value. The angle is specified by arc degree method using π (pi function).

use Math::Trig 'pi'; cos(pi/3);

The pi function is defined in Math::Trig module.

### cos function programming example

The following is a cos function programming example.

use strict; use warnings; use Math::Trig 'pi'; # cos(60°) = 1/2; print "cos(π/3) = " . cos(pi/3) . "\n";

### Other trigonometric functions

Perl also has sin function in core functions.

The following article explains how to use other trigonometric functions such as tangent.