(PHP 4, PHP 5)
sin — Sine
sin() returns the sine of the arg parameter. The arg parameter is in radians.
A value in radians
The sine of arg
Example #1 sin() example
<?php
// Precision depends on your precision directive
echo sin(deg2rad(60));  //  0.866025403 ...
echo sin(60);           // -0.304810621 ...
?>