Lesson 11-1 Pages 470-473

Squares and Square Roots

What you will learn!

How to find squares of numbers and square roots

of perfect squares.

SquareSquarePerfect squarePerfect squareSquare rootSquare rootRadical signRadical sign

What you really need to know!

The product of a number and itself is the square of the number. Numbers like 4, 25, and 2.25 are called perfect squares because they are squares of rational numbers. The factors multiplied to form perfect squares are called square roots.

What you really need to know!

Both 5•5 and (-5)(-5) equal 25. So, 25 has two square roots, 5 and -5. A radical sign, √ , is the symbol used to indicate the positive square root of a number. So, √25 = 5.

NumberNumber 11 22 33 44 55 66 77

SquareSquare 11 44 99 1616 2525 3636 4949

Perfect Perfect SquareSquare 11 44 99 1616 2525 3636 4949

Square Square RootRoot 11 22 33 44 55 66 77

Link to Pre-Made Lesson

Example 1:

Find the square of 5.

5 • 5 = 25

Example 2:

Find the square of 19.19 • 19 = 361

Example 3:

A 6 kilogram ball is soaring through the air at 5 meters per second.

If kinetic energy = ½mv2, where m is the mass and v is the speed, what is the ball’s kinetic energy?

2mv2

1KE

2562

1KE

5262

1KE

523KE

75KE

22 /75 smkg

Example 4:

.36Find

Since 6 x 6 = 36, the square root of 36 is 6.

636

Example 5:

.676FindSince 26 x 26 = 676, the square root of 676 is 26.

26676

Example 6:

A checkerboard is a square with an area of 1,225 square centimeters. What are the dimensions of the checkerboard?

Since 35 x 35 = 1,225, the dimensions of the board would be 35 cm x 35 cm.

Page 472

Guided Practice

#’s 4-12

Pages 470-471 with someone at home and study

examples!

Read:

Homework: Page 472-473

#’s 13-38, 46, 47, 50-53

Lesson Check 11-1

Page

590

Lesson 11-1