# ATAN2 function

The ATAN2 function returns the arctangent, in radians, of the quotient of the two arguments.

Upon successful completion, the function returns the arc tangent of y/x in the range -pi to pi radians, where y is the first argument and x is the second argument. The specified numbers must be DOUBLE PRECISION numbers.

- If either argument is NULL, the result of the function is NULL.
- If the first argument is zero and the second argument is positive, the result of the function is zero.
- If the first argument is zero and the second argument is negative, the result of the function is the double value closest to pi.
- If the first argument is positive and the second argument is zero, the result is the double value closest to pi/2.
- If the first argument is negative and the second argument is zero, the result is the double value closest to -pi/2.

The data type of the returned value is a DOUBLE PRECISION number.

## Syntax

    ATAN2 ( y, x )

Parent topic: Built-in functions