ATAN function

Arc tangent function. ATAN(x) returns the arc tangent of x. The arc tangent function is the inverse function of the tangent function and calculates the angle for a given tangent x. The result is an angle expressed in radians. To convert from radians to degrees, use the DEGREES function.

The argument x can be a real number, a complex number, or a matrix. When it is a matrix, the function returns a matrix with the same dimensions and with the ATAN function applied to all elements.