arctangent function
The arctangent of x is defined as the inverse tangent function of x when x is real (x ââ). When the tangent of y is equal to x: tan y = x. Then the arctangent of x is equal to the inverse tangent function of x, which is equal to y: arctan x= tan-1 x = y. Example. arctan 1 = tan-1 1 = Ï/4 rad = 45Â° Graph of arctan. Arctan rules