arc tan function

The atan function is an inverse trigonometric function. The atan function returns the arc tangent (inverse of tangent) of the input expression.

Syntax:

double atan(n)

Semantics:

• n: The argument n is an expression that resolves to a number.

• return type: double.

  The resultant angle is expressed in radians and is in the range -pi/2 through -pi/2 with the following exceptions:

  • Returns a NULL value in the following cases:

    • n resolves to a NULL value

    • n does not resolve to a number

  • Returns NaN if n resolves to NaN.

  • Results in a zero with the same sign as n, when n is zero.

Example 1 - arc tan function

SELECT atan(n) FROM Archery

Value of n	Output
1	0.7853981633974483
sqrt(3)	1.0471975511965976