ARCTANGENT
THE BOX'S MAIN HELP:
This fucntion returns a float between [-PI/2,PI/2], the arctangent of A. Arctangent is the inverse of the tangent function where the atan(x) = y if and only if tan(y) = x.
A (input):
This may be any real number.
OUT (output):
This fucntion returns a float between [-PI/2,PI/2], the arctangent of A. Arctangent is the inverse of the tangent function where the atan(x) = y if and only if tan(y) = x.