arctan/1

Returns the arc tangent of a real argument

REAL is arctan(REAL) -(i)

Returns the arc tangent of the real argument X.

Compatibility: Visual Prolog.

Remarks:

The expression Angle = arctan(X) binds Angle (if it is free) to the result, or succeed/fail if Angle is already bound.

The returned Angle is measured in radians and belongs to the range from -Pi/2 till Pi/2.

Fail: Never fails

Errors: No errors

see also:

cos/1

sin/1