Definition
Cube root
The cube root of a number is the value that cubes to make that number.
What it means
Ask, “What number can fill all three factor places?” A cube root undoes cubing. Because three negative factors make a negative product, negative numbers also have real cube roots.
Remember it
Cube root asks for one factor copied three times.
Example
∛(−125) = −5 because (−5) × (−5) × (−5) = −125.
Watch for
Taking a cube root is not dividing by 3: 64 ÷ 3 is not ∛64.
Common mix-up
A negative number can have a real cube root, unlike a negative number’s real square root.
Exact meaning
The cube root of a real number x is the unique real number y such that y³ = x.