acos
PHP function
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(PHP 4, PHP 5, PHP 7, PHP 8)
Arc cosine
Description
acos(float $num): float
Returns the arc cosine of num in radians. acos() is the inverse function of cos(), which means that $num == cos(acos($num)) for every value of num that is in the domain of acos().
Parameters
numThe argument to process
Return Values
The arc cosine of num in radians.