Arc tangent of two numbers. ATAN2(y,x) returns the arc tangent of the two numbers x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result.
The result is an angle expressed in radians. To convert from radians to degrees, use the DEGREES function.
In terms of the standard arc tangent function, atan2 can be expressed as follows:
Note that in Excel the parameters y and x are reversed.
- ATAN function: returns the arc tangent of a number.
- DEGREES function: converts radians to degrees.
- Trigonometric functions
- atan2 function on Wikipedia.