ACOS
Returns the arc cosine of x, that is, the value whose cosine is x. Returns NULL if x is not in the range -1 to 1.
Syntax
ACOS(x)
Arguments
| Arguments | Description | 
|---|---|
| x | The angle, in radians. | 
Return Type
A Float64 data type value.
Examples
mysql> SELECT ACOS(1);
+---------+
| ACOS(1) |
+---------+
|       0 |
+---------+
1 row in set (0.01 sec)
mysql> SELECT ACOS(1.0001);
+--------------+
| ACOS(1.0001) |
+--------------+
|         NULL |
+--------------+
1 row in set (0.02 sec)