Download Chapter 8.7(a) Solving Quadratic Equations by Using Square Roots

Chapter 8.7(a) Solving Quadratic Equations by Using Square Roots.notebook March 03, 2017
Homework Questions???
Bellwork:
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At times factoring or graphing is not the best method for solving a quadratic equation. Square Roots can be helpful to solve these equations.
Since:
Chapter 8.7 Solving Quadratic Equations by Using Square Roots
Solve quadratic equations by using square roots.
(4)(4) = 42 = 16 and
√16 = 4
(­4)(­4) = (­4)2 = 16
√16 = ­4
The square root of 16 can be positive or negative 4.
±√16 = ± 4
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1) Solve using Square Roots
Square Root Property
Word
To solve a quadratic equation in the form x2 = a, take the square root of both sides
Numbers
Algebra
x2 = 15
x = ±√15
If x2 = a and a is a positive real number, then x = ± √15
Solve using square roots:
a. x2 = 169
b. x2 = ­49
c. x2 = 24
x2 = 36
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1
Chapter 8.7(a) Solving Quadratic Equations by Using Square Roots.notebook March 03, 2017
2) Solve using Square Roots (isolate the squared part 1st)
3) Solve using Square Roots (isolate the squared part 1st)
a. x2 + 7 = 7
b. 16x2 ­ 49 = 0
a. x2 ­ 64 = 0
b. 4x2 = 9
c. (x ­ 3)2 = 25
d. x2 + 8 = 81
c. (x + 5)2 = 36
d. 3x2 ­ 9 = 36
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4) Ms. Pirazada is building a retaining wall along one of the long sides of her rectangular garden. The garden is twice as long as it is wide. It also has an area of 578 square feet. What will be the length of the retaining wall?
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For the quadratic equation x2 + a = 0, determine each value of a will result in two rational solutions. How do you know?
a. ­½
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b. ½
c. ­¼
d. ¼
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Homework
P. 571­573 #1­12 (all), 17­27(odds), 43
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