The ATAN function returns the arctangent, or inverse tangent, of a number. The arctangent is the angle whose tangent is number. The returned angle is given in radians in the range to .
|number||The tangent of the angle you want|
|2||=ATAN(-1)||-0.785398163||Arctangent of -1 in radians, -pi/4|
|3||=ATAN(1)||0.785398163||Arctangent of 1 in radians, pi/4|
|4||=ATAN(1)*180/PI()||45||Arctangent of 1 in degrees|
|5||=DEGREES(ATAN(1))||45||Arctangent of 1 in degrees|
Note: If you want the angle returned by the ATAN function to be expressed in degrees, you can convert it, using the DEGREES function: =DEGREES(radians)
Common Function Error(s)
|Problem||What went wrong|
|#VALUE!||Occurs if the supplied number argument is not recognized as a numeric value|
The arctangent is the inverse of the tangent. Therefore, for the simple right-angle triangle at right, the arctangent of the opposite side (a), divided by the adjacent side (b), is equal to the angle A. Arctangent is calculated as:
See Wikipedia for more information on Inverse Trigonometric Functions.