float acos(float $val)
(PHP 4, PHP 5)
| $val | Value to compute the arc cosine for. |
|---|---|
| RETURNS | Computes the trigonometry function arc cosine for the degree in radians ($val). |
This function computes the arc cosine for the argument $val which is the degree in radians.
// compute the arc cosine for 1.4 radians echo 'acos(1.4) = ' . acos(1.4);