# ACOS function

## Description

Arccosine function. ACOS(x) returns the arccosine of x. The arccosine function is the inverse function of the cosine function and calculates the angle for a given cosine. X must be in the [-1..1] range. The result is an angle expressed in radians. To convert from radians to degrees, use the DEGREES function.

## Examples

ACOS(0) equals 1.5707963 (=PI/2)

ACOS(1) equals 0