1//thank you rahmatjon
2Example:
3<?php
4 $arg=0.5;
5 $val=acos($arg);
6 echo "acos(" . $arg . ") = " . $val . " radians.<br/>";
7 echo "Pi value = " . pi() . "<br/>";
8 echo "acos(" . $arg . ") = " . $val/pi()*180 . " degrees<br/>";
9?>
10
11