acos

Arc cosine

Description

float acos(float $num)

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

  • cos
  • acosh
  • asin
  • atan