Question

Does anyone know cube roots

Answer 1

Cube Root

A cube root goes the other direction:

3 cubed is 27, so the cube root of 27 is 3

3 cube root direction 27
The cube root of a number is ...
... a special value that when cubed gives the original number.

The cube root of 27 is ...
... 3, because when 3 is cubed you get 27.

tree root
Note: When you see "root" think

"I know the tree, but what is the root that produced it?"

In this case the tree is "27", and the cube root is "3".

Here are some more cubes and cube roots:


4

64
5

125
6

216

Example: What is the Cube root of 125?

Well, we just happen to know that 125 = 5 × 5 × 5 (if you use 5 three times in a multiplication you will get 125) ...

... so the answer is 5

The Cube Root Symbol
cube root symbol
This is the special symbol that means "cube root", it is the "radical" symbol (used for square roots) with a little three to mean cube root.

You can use it like this: cube root 27 = 3 (we say "the cube root of 27 equals 3")



You Can Also Cube Negative Numbers

Have a look at this:

When we cube 5 we get 125: 5 × 5 × 5 = 125

When we cube −5 we get −125: −5 ×−5 × −5 = −125
So the cube root of −125 is −5

Perfect Cubes

The Perfect Cubes are the cubes of the whole numbers:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 etc
Perfect Cubes: 1 8 27 64 125 216 343 512 729 1000 1331 1728 2197 2744 3375 ...
It is easy to work out the cube root of a perfect cube, but it is really hard to work out other cube roots.

Answer 2

Also just to add, we can express roots with exponential fractions. For instance

\( 125^{\frac{1}{3}} = \sqrt[3]{125} = 5 \)

Answer 3

when i was doing a problem about cube roots and i was trying to answer it there was like a little symbol in front of the cube root