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 1 - 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