ACOS

The ACOS function returns the arc cosine of the argument as an angle expressed in radians. The ACOS and COS functions are inverse operations.

ACOS(expression)

expression: An expression that returns a value of any built-in numeric data type (except for DECFLOAT), character-string, or graphic-string data type. A string argument is cast to double-precision floating point before evaluating the function. For more information about converting strings to double-precision floating point, see DOUBLE_PRECISION or DOUBLE. The value must be greater than or equal to -1 and less than or equal to 1.

The data type of the result is double-precision floating point. If the argument can be null, the result can be null; if the argument is null, the result is the null value.

The result is greater than or equal to 0 and less than or equal to π.

Example

Assume the host variable ACOSINE is a DECIMAL(10,9) host variable with a value of 0.070737202.
```
   SELECT ACOS(:ACOSINE)
     FROM SYSIBM.SYSDUMMY1
```
Returns the approximate value 1.49.