Root

1. Root of a number

The root of a number x is another number, which when multiplied by itself a given number of times, equals x. For example the second root of 9 is 3, because 3x3 = 9.

• The second root is usually called the square root.
• The third root is susually called the cube root

2. Roots of a polynomial

The roots of a polynomial are the values of the variable that cause the polynomial to evaluate to zero. For example the roots of are +2 and -2.

See Roots of a polynomial.