1. Class Greeting

2. Squares and Square Roots
Lesson 9-1a
Squares and Square Roots

3. Objective: The student will define radical, square root, cube root, nth root and principal nth root of a number. The student will find square roots, cube roots, nth roots and principal nth roots of real numbers.

5. Roots Number a Equal Factors Principal nth Root Type
25 =  Square root
–27 = (–3) (–3)(–3)(–3) – Cube root
16 = (–2) (–2)(–2)(–2)(–2) Fourth root

6. Finding the Square Roots of Numbers
a. The positive number 81 has two square roots, because 92 = (9)(9) = 81 and (–9)2 = (–9)(–9) = 81. The principal nth root is 9.
b. The positive number has two square roots, and
because and
The principal nth root is .
c. The number 0 has only one square root: 0. The principal nth root is 0.
d. The negative number –4 has no square root because there is no real number that can be multiplied by itself to obtain –4. Therefore it has no principal nth root.

7. Finding the Square Roots of Numbers
1. Find the positive and negative square roots of each number.
a. 81 b.
c. 0
d. –4
Answer: 9 and –9
Answer: 9
Answer: 2/3 and –2/3
Answer: 2/3
Answer: Impossible
Answer: 0
Answer: impossible
Answer: impossible
2. Find the principal square root of each number.

8. Find Square Roots A.
Answer: 8
Lesson 1 Ex1

9. Find Square Roots B.
Answer: –11
Lesson 1 Ex1

10. A.
A. 624
B. 12.5
C. 5
D. –5 A B C D
Lesson 1 CYP1

11. B.
A. 12
B. –12
C. –72
D. –20,736 A B C D
Lesson 1 CYP1

12. Lesson Summary:
Objective: The student will define radical, square root, cube root, nth root and principal nth root of a number. The student will find square roots, cube roots, nth roots and principal nth roots of real numbers.

13. Preview of the next Lesson:
Objective: The student will define perfect square, rational and irrational numbers. The student will classify numbers as rational or irrational. The student will learn the technique for estimating radicals.

14. Kahoot!

15. Stand Up Please