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.

The argument x can be a real number, a complex number, or a matrix. When it is a matrix, the function returns a matrix with the same dimensions and with the ACOS function applied to all elements.