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Squares and Square Roots Lesson 9-1a Squares and Square Roots
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.
Roots Number a Equal Factors Principal nth Root Type 25 = 52 5 5 5 Square root –27 = (–3)3 (–3)(–3)(–3) –3 Cube root 16 = (–2)4 (–2)(–2)(–2)(–2) 2 Fourth root
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.
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.
Find Square Roots A. Answer: 8 Lesson 1 Ex1
Find Square Roots B. Answer: –11 Lesson 1 Ex1
A. A. 624 B. 12.5 C. 5 D. –5 A B C D Lesson 1 CYP1
B. A. 12 B. –12 C. –72 D. –20,736 A B C D Lesson 1 CYP1
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.
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.
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