1-8: Roots What is a Square Root ? √16 A square root of a number is one of its two equal factors. What is a Perfect Square ? √25 A perfect square are numbers such as 1, 4, 9, 16, 25,… because they are squares of integers. Square Roots What is a Radical Sign ? Summary: 2 5 = 25 so 5 is a square root of 25. √ A radical sign , √ , is used to indicate the principal square 2 root. If n = a, then n = ± a. Example 1a: Page 72 Find each square 1. Find the square root: root of each 9 √ 16 number. Find each square root: - √100 Example 1c: Page 72 √− 100 Page 1d: Page 72 3 What are Roots ? What is Cubes ? Cube Perfect √27 3 If x = y, then x is the cube root of y. 3 8 = 2 ∙ 2 ∙ 2 or 2 A cube root of a number is one of its three equal factors. Numbers such as 8, 27, and 64 are perfect cubes because they are the cubes integers. Summary: of Example 2h: Page 73 Example 2i: Page 73 Find root: Find root: the cube 1. What number times itself three 3 √729 times equal 729? the cube 3 √− 64 Example 3k: Page 74 An aquarium in the shape of a cube that will hold 25 gallons of water has a volume of 3.375 cubic feet. Solve 3 s = 3.375 to find the length of one side of the aquarium. Summary: