Sam

A radical is a root sign. Radicals need a number to define what root it is. With square roots, the two is generally left off. With cube roots a 3 is written in little numbers on top of the left side of the radical. The index tells how many times the root needs to be multiplied by itself to equal the radical.

For example,

1. The square root of 9 is 3. This means that 3 x 3 = 9

2. The cube root of 64 is 4. This means that 4 x 4 x 4 = 64