A square root of a number is a value that can be multiplied by itself to give the original number. For example, a square root of 9 is 3, because when 3 is multiplied by itself we get 9. Note that -3 is also a square root of 9, because -3 x -3  = 9.

In mathematics, a cube root of a number x is a number a such that a³ = x. All real numbers except zero have exactly one real cube root.