acos

(PHP 4, PHP 5, PHP 7, PHP 8)

acos — 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

num

The argument to process

Return Values

The arc cosine of num in radians.

See Also