• Find square roots of perfect squares. • perfect square • square root • radical sign
Lesson 3-1 Ideas/Vocabulary
• Find square roots of perfect squares.
• perfect square• square root• radical sign
Lesson 3-1 TEKS
Reinforcement of TEKS 7.1 The student represents and uses numbers in a variety of equivalent forms. (C) Represent squares and square roots using geometric models.
Lesson 3-1 Example 1
Find Square Roots
Answer:
indicates the positive square root of 81.
Interactive Lab: Square Roots
Find
A. A
B. B
C. C
D. D
Lesson 3-1 Example 1 CYP
A B
C D
0% 0%0%0%
A. 4
B. 6
C. 8
D. 16
Find
Lesson 3-1 Example 2
Answer:
indicates the negative square root of
Find Square Roots
Find
A. A
B. B
C. C
D. D
Lesson 3-1 Example 2 CYP
A.
B.
C.
D.
Find
A B
C D
0% 0%0%0%
Lesson 3-1 Example 3
Find Square Roots
Answer: Since (1.2)2 = 1.44 and (–1.2)2 = 1.44, = ±1.2, or 1.2 and –1.2.
indicates both the positive and negative square roots of 1.44.
Find
A. A
B. B
C. C
D. D
Lesson 3-1 Example 3 CYP
A B
C D
0% 0%0%0%
A. ±1.2
B. ±1.25
C. ±1.5
D. ±1.75
Find
x2 = 225 Write the equation.
Lesson 3-1 Example 4
ALGEBRA Solve x2 = 225.
Answer: The equation has two solutions, 15 and –15.
Use Square Roots to Solve an Equation
x = 15 and x = –15 Check 15 15 = 225 and
(–15) (–15) = 225
x = Definition of square root
A B
C D
0% 0%0%0%
A. A
B. B
C. C
D. D
Lesson 3-1 Example 4 CYP
A. –9
B. 9
C. –9 and 9
D. –8 and 8
ALGEBRA Solve x2 = 81.
Area is equal to the square of the length of a side.
Lesson 3-1 Example 5
MUSIC The art work on the square picture in a compact disc case is approximately 14,161 mm2 in area. Find the length of each side of the square.
Words
Variable
Equation
Let s represent the length of a side.
14,161 = s2
Use Square Roots to Solve a Problem
Lesson 3-1 Example 5
Answer: The length of a side of a compact disc case is about 119 millimeters since distance cannot be negative.
14,161 = s2 Write the equation.
= s Definition of square rootENTER
=2ndc
14161 Use a calculator.
119 = s
Use Square Roots to Solve a Problem
A B
C D
0% 0%0%0%
A. A
B. B
C. C
D. D
Lesson 3-1 Example 5 CYP
A. 85 inches
B. 93 inches
C. 95 inches
D. 105 inches
ART A piece of art is a square picture that is approximately 11,025 square inches in area. Find the length of each side of the square picture.