PHP Functions Essential Reference

cos

float cos(float radians) 

Returns the cosine for the given radians

value.

Returns:

Cosine of a value

Description:

Returns the cosine of the value given by radians , which as its name suggests is to be given in radians.

Version:

PHP 3, PHP 4

See also:

acos() 
asin() 
atan() 
atan2() 
sin() 
tan() 

Example:

Calculate the cosine of a value

$rad = pi() / 2; echo "The cosine of $rad = ", cos($rad);