float atan2(float $y, float $x)
(PHP 4, PHP 5)
| $y | Numerator of a fraction (y / x) which is the argument for the arc tangent. |
|---|---|
| $x | Numerator of a fraction (y / x) which is the argument for the arc tangent. |
| RETURNS | The arc tangent of the fraction ($y / $x). This result will be between -PI and PI. |
This function computes the arc tangent for the arguments $y and $x which represent the numerator and denominator of the fraction (y / x). The result of this trigonometry function is a value between -PI and PI where PI is roughly (3.14.15926).
// compute the inverse hyperbolic sine for 1.4 radians echo 'atan2(1.4, 2.0) = ' . atan2(1.4, 2.0);