mysql>
mysql> SELECT SQRT(4);
+---------+
| SQRT(4) |
+---------+
| 2 |
+---------+
1 row in set (0.00 sec)
mysql>
mysql> SELECT SQRT(20);
+-----------------+
| SQRT(20) |
+-----------------+
| 4.4721359549996 |
+-----------------+
1 row in set (0.00 sec)
mysql>