ReferenceExpressionsTrigonometryArc TangentReturn the arc tangent of a.atan( a )# Return the arc tangent of a. Description# atan( a ) Return the arc tangent of a. Parameters# a Angle in radians [-1 to +1] Return value# arc tangent of a Example usage# atan( 1 ) Returns 0.7854… Last updated Sep 2, 2019PreviousArc SineNextCosine