(PHP 4, PHP 5)
sin — Sine
$arg
    )
   sin() returns the sine of the arg
   parameter.  The arg parameter is in radians.
  
argA 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 ...
?>