MySQL in a Nutshell, 2nd Edition

Name

ACOS()

Synopsis

ACOS(number)

This function returns the arc cosine, in radians, of a given number. For input greater than 1 or less than –1, NULL is returned. Here is an example:

SELECT ACOS(.5), ACOS(1.5);

+----------+-----------+
| ACOS(.5) | ACOS(1.5) |
+----------+-----------+
| 1.047198 |      NULL |
+----------+-----------+