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Objective
Find square roots of perfect squares
Vocabulary
Perfect Square
Any number that is a square of a whole number
1, 4, 9, 16, 25, . . .
Vocabulary
Square root
One of a numbers two equal factors
(the opposite of squaring a number)
Vocabulary
Radical sign
A symbol used to indicate the positive square
root
81
Vocabulary
Principal square root
A positive square root
Example 1 Find a Square Root
Example 2 Find the Negative Square Root
Example 3 Use Square Roots to Solve an Equation
Example 4 Use an Equation to Solve a Problem
Write problem
Find
Use calculator
Put 81 in calculator
Push the  x key
81 [  x ]
9
indicates the positive
square root of 81.
Answer: 9
1/4
Find
Answer: 8
1/4
Write problem
Find
Use calculator
Put 144 in calculator
144 [  x ]
-12
12
Push the  x key
indicates the negative
square root of 144
Answer: -12
2/4
Find
Answer: ─ 6
2/4
Write the problem
ALGEBRA Solve
Ask “what is being done
to the variable?”
The variable is being
squared
Do the inverse on both
sides of the equal sign
The inverse of squaring
is finding the square root
3/4
ALGEBRA Solve
Find
Bring down the equal
sign
Find 49
Find 64
x =
Answer:
Since same sign when
multiplying integers is a
positive answer there are
2 solutions
3/4
ALGEBRA Solve
Answer:
3/4
MUSIC The art work of the square picture in a
compact disc case is approximately
in
area. Find the length of each side of the square.
Words
Area
is equal to
Variable
A
=
Equation
14,161
=
4/4
the square of the
length of a side.
Ask “what is being done to the
variable?”
14,161 = s2
The variable is being squared
Do the inverse on both sides of the
equal sign
119 = s
The inverse of squaring is finding
the square root
Find 14,161
Find s
Answer: Length of side = 119 mm
4/4
*
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.
Answer: length of side = 105 inches
4/4
Assignment
Lesson 3:1
Square Roots
14 - 37 All