1. SQL Reference Guide
  2. Built-in Functions
  3. Functions of Mathematical Operations
  4. arc cosine function

arc cosine function

The acos function is an inverse trigonometric function. The acos function returns the arc cosine (inverse of cosine) of the input expression.

Syntax:

double acos(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 0.0 through pi 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 in the following cases:
      • n resolves to NaN
      • absolute value of n is greater than one
      • n resolves to positive/negative infinity

Example 12-71 arc cosine function

SELECT acos(n) FROM Archery
Value of n Output
1 0.0
0 1.5707963267948966
sqrt(3)/2 0.5235987755982989
0.5 1.0471975511965979
-1 3.141592653589793