Calculates the arc cosine of an angle.
ACos ( n )
| Argument | Description | 
|---|---|
| n | The ratio of the lengths of two sides of a triangle for which you want a corresponding angle (in radians). The ratio must be a value between -1 and 1. | 
Double. Returns the arc cosine of n if it succeeds.
This expression returns 0:
ACos(1)
This expression returns 3.141593 (rounded to six places):
ACos(-1)
This expression returns 1.000000 (rounded to six places):
ACos(.540302)