1. Solving Quadratic Equations by Finding Square Roots

2. Square Roots
Square roots: a number that produces a specified quantity when multiplied by itself.
Example: =  (7 × 7 = 49)
Types of square roots:
Positive: = 9
Negative: − = -10
Zero Square Root: 0 = 0
Two square roots: ± = ±0.5
Undefined: −4 (no square root)

3. Perfect Squares
Perfect Squares: numbers whose square roots are integers. 82 64 92 81
102
100
112
121
122
144
132
169
142
196
152
225 12 1 22 4 32 9 42 16 52 25 62 36 72 49

4. Not Perfect Squares
Numbers that are not perfect squares must be written using the radical symbol or approximated.  These numbers are irrational.
Irrational Numbers: numbers that cannot be written as fractions
Examples: or

5. Evaluating Square Roots
− 121
1.44
0.09 7

6. Evaluating a Radical Expression
When a = 1, b = -2 and c = -3, evaluate: 𝑏 2 −4𝑎𝑐

7. Evaluating a Radical Expression
When a = 2, b = 4
10±2 𝑏 𝑎

8. Falling Object Model
Formula: ℎ=−16 𝑡 2 +s h = ground level t = time s = initial height

9. ℎ=−16 𝑡 2 +s
An engineering student is in an “egg dropping contest.” The goal is to create a container for an egg so it can be dropped from a height of 32 feet without breaking the egg. To the nearest tenth of a second, about how long will it take for the egg’s container to hit the ground. Assume there is no air resistance. (h = 0 when it hits the ground)

10. ℎ=−16 𝑡 2 +s
An engineering student is in an “egg dropping contest.” The goal is to create a container for an egg so it can be dropped from a height of 64 feet without breaking the egg. To the nearest tenth of a second, about how long will it take for the egg’s container to hit the ground. Assume there is no air resistance.

11. Homework
Page: 507
8-20 evens and 36, 38.