ACos
Computes the arc-cosine, or inverse cosine, of a number.
Syntax
ACos(number)ArcCos(number)
number = number whose arccosine you want to calculate, must be between -1 and +1
Remarks
The return value is an expressed in Radians, in an interval from zero to PI.
If number is outside the interval from -1 to +1, the function will return a zero.
If you want a result expressed in degrees, you can multiply it by 180/PI or use the Degrees function.
Example
ACos(0) = pi/2Degrees(ACos(-0.5)) = 120