MySQL in a Nutshell, 2nd Edition

Name

ATAN2()

Synopsis

ATAN2(number, number)

This function returns the arctangent, in radians, of X and Y for a point on a Cartesian plane. The value for Y is given as the first argument and X as the second. The reverse function is TAN(). Here is an example:

SELECT ATAN2(10, 5);

+--------------+
| ATAN2(10, 5) |
+--------------+
|     1.107149 |
+--------------+