# ATAN2

ATAN2(x_num, y_num)

Returns the arc-tangent of the specified x and y co-ordinates.

 x_num The x-coordinate of the point. y_num The y-coordinate of the point.

 REMARKS
 * For an illustrated example refer to the [[Trigonometric Functions]] page.* The arc-tangent of an angle is the inverse of the TAN function.* ATAN2(x_num , y_num) equals ATAN(y_num / x_num), except that "x_num" can equal 0 in ATAN2.* The arc-tangent is the angle from the x-axis to a line containing the origin (0, 0) and a point with coordinates ("x_num", "y_num").* If "x_num" = 0 and "y_num" = 0, then #DIV/0! is returned.* The returned angle is given in radians between -PI and PI (excluding -PI).* A positive result represents an anti-clockwise angle (from the x-axis).* A negative result represents a clockwise angle (from the x-axis).* If your argument is in degrees, multiply it by PI/180 to convert it to radians.* If you want to convert the result from radians to degrees, multiply it by 180/PI.* You can use the DEGREES function to convert from radians to degrees.* For the Microsoft documentation refer to support.microsoft.com* For the Google documentation refer to support.google.com

 A 1 =ATAN2(1,1) = 0.785 2 =ATAN2(-1,-1) = -2.356 3 =ATAN2(2,3)=ATAN(3/2) = True 4 =ATAN2(-100,-100) = -2.356 5 =ATAN2(0,1) = 1.571 6 =ATAN2(0,5) = 1.571 7 =ATAN2(0,-0.5) = -1.571 8 =ATAN2(-0.5,0) = 3.142 9 =ATAN2(-1,-1)*180/PI() = -135 10 =ATAN2(0,0) = #DIV/0! 11 =ATAN2("some text",1) = #VALUE! 12 =ATAN2(1,"some text") = #VALUE!