Square and Cube Roots MRS. RAUCH. How do we square a number? Can we square negative numbers?

Square and Cube RootsMRS. RAUCH

How do we square a number?

Can we square negative numbers?

Square Roots

Square Roots

Perfect Squares

What does cubing a number mean?

Cubing a number

To cube a number, you just multiply that number by itself 3 times

Example: 3 cubed is or 3 x 3 x 3The little 3 means the number appears

3 times when multiplying

Practice with cubes

4 cubed

5 cubed

6 cubed

Cube Roots

A cube root goes the other direction

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

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

When you see “root” think……I know the tree but what is the root that produced it?

Practice with Cube Roots

What is the cube root of 125?

What is the cube root of 8?

What is the cube root of 1000?

The cube root sign

This is a special symbol that means “cube root”, it is the radical symbol (used for square roots) with a little 3 to mean cube root

You can use it like this…. = 3 We say, “the cube root of 27 is 3

Can you cube negative numbers?

Cubing Negative Numbers

When we cube 5 we get…. When we cube -5 we get…

So can cube roots be negative?

Perfect Cubes