1. 5.3 Solving Quadratic Equations by Finding Square Roots
OBJ: To solve quadratic equations by finding square roots and model real-life problems
5.3 Solving Quadratic Equations by Finding Square Roots
Do Now:
How would you solve the equation x2 = 100 ?

2. How would you solve the equation: x2 = 4 (take the square root of each side)
* Remember, the square root of a positive # has 2 answers! (one + and one -)

3. Radical
Radical sign
Radicand

4. Properties of Square Roots
Product Property
Like:
Quotient Property
Like:

5. Examples: 1. 2. 3.

6. Rationalizing the Denominator
You CANNOT leave a radical in the denominator of a fraction!
No tents in the basement!!!!
(the numerator is OK)
To “rationalize” the denominator:
multiply the top & bottom of the fraction by the radical

7. Can’t have a tent in the basement!
Examples: 4. 5.
Can’t have a tent in the basement!

8. Solving Quadratic Equations
x2 = -9
-5x2 = -12
x2 =
(x-2)2=21
(x-2)2 = 7

9. 9.
x2-6=42
+6 +6
4x2=48
x2 = 12

10. Falling Objects! Use h = -16t2 + h0
Height of the object after it has fallen
Object’s initial height
# of seconds after the object is dropped

11. Ex 10:
The tallest building in the USA is in Chicago, Illinois. It is 1450 ft. tall. How long would it take a penny to drop from the top of the building to the ground?