top of page
Cube Root
See It in Action
Two examples of the idea done right—and one common look-alike that is not right.
EXAMPLE
EXAMPLE
NON-EXAMPLE
Definition
The cube root of a number is the value that, when multiplied by itself three times, gives the original number. It is the opposite (or inverse) operation of cubing a number.
The cube root of a number x is written as:
For example:
The cube root of 27 is 3, because 3 • 3 • 3 = 27, so the cube root of 27 equals 3.
The cube root of -8 is -2, because -2 • -2 • -2 = -8, so the cube root of -8 equals -2.
Unlike square roots, which only have non-negative real solutions when dealing with positive numbers, cube roots can have both positive and negative real solutions. For example, the cube root of -8 is -2, while the cube root of 8 is 2.
bottom of page