The arctan function returns the arctangent in radians of the parameter passed to it. So if X is the parameter passed to this function, then the value returned by this function Y is the angle in radians satisfying the following equation:
X = tan(Y)
The type of the value returned by this function is always real.
The arctan function's only parameter is a numeric expression (i.e. an expression of integral type or of real type).
arctan(0.5) returns 4.64E-1
Operating Systems: All Standard Pascal: Yes