POW
POWER

POW(X,Y)
POWER(X,Y)

Devuelve el valor de X elevado a la potencia Y:

mysql> SELECT POW(2,2);
+----------+
| POW(2,2) |
+----------+
| 4.000000 |
+----------+
1 row in set (0.02 sec)

mysql> SELECT POW(2,-2);
+-----------+
| POW(2,-2) |
+-----------+
|  0.250000 |
+-----------+
1 row in set (0.00 sec)