arc tan2 function

The atan2 function is an inverse trigonometric function. The atan2 function is a two-argument arc tangent (inverse of tan) function, which returns the arc tangent of a coordinate or point in two-dimensional space (n1, n2) calculated as atan(n2/n1).

Syntax:

double atan2(n1,n2)

Semantics:

• n1, n2: The arguments n1 and n2 are expressions that resolve to numbers.

• return type: double.

  The resultant angle is expressed in radians and is in the range -pi through pi with the following exceptions:

  • Returns a NULL value in the following cases:

    • If either of the arguments resolves to a NULL value

    • If either of the arguments does not resolve to a number

  • Returns a NaN if either of the arguments resolves to NaN.

Example 1 - arc tan2 function

SELECT atan2(n1,n2) FROM Archery

Value of n1	Value of n2	Output
1	1	0.7853981633974483
1	sqrt(3)	1.0471975511965976
2	0	1.5707963267948966