1. Quadratic Formula

2. Table of Contents
46: Warm-Up, Guided Practice
47: How Do I Use the Quadratic Formula to Factor Trinomials?

3. Warm-Up
Solve for the roots: 1. x2 – 9 = x2 + 4 = 3

4. Warm-Up Answers Solve for the roots: 1. x2 – 9 = 0 2. -x2 + 4 = 3 + 9
___________
___________
- 4
- 4
x2 = 9
___ -1
-x2 = -1
___ -1
x =  3
x2 = 1
Roots:
(3, 0)
x =  1
(-3, 0)
Roots:
(1, 0)
(-1, 0)

5. Learning Intention/Success Criteria
LI: We are learning to factor quadratics with the quadratic formula SC: I know how to -simplify square roots -memorize the quadratic formula -locate solutions by using the quadratic formula -use integer operations -substitute values into an equation

6. EQ: How Do I Factor Quadratics Using Completing the Square?
5/11/2019

7. Do the quad solve video

8. The formula for the roots of a quadratic equation
Quadratic Formula
The formula for the roots of a quadratic equation

9. Example 1: Solve for the roots: 2x2 + 3x – 9 = 0 A: B: C: 2 3 -9

10. (-3, 0)
Roots:

11. Guided Practice 1
Use the quadratic formula to solve the equation: 2x2 – 11x + 12 = 0

12. Guided Practice 1
Use the quadratic formula to solve the equation: 2x2 – 11x + 12 = 0
Roots:
(4, 0)
(1.5, 0)

13. Guided Practice 2
Use the quadratic formula to solve the equation: x2 – 4x + 3 = 0

14. Guided Practice 2
Use the quadratic formula to solve the equation: x2 – 4x + 3 = 0
Roots:
(3, 0)
(1, 0)

15. Example 2: Solve for the roots: x2 + 8x – 1 = 0 A: B: C: 1 8 -1

16. Roots:
(0.12, 0)
(-8.12, 0)

17. Guided Practice 3
Use the quadratic formula to solve the equation: 5x2 – x – 2 = 0

18. Guided Practice 3
Use the quadratic formula to solve the equation: 5x2 – x – 2 = 0
Roots:
(0.74, 0)
(-0.54, 0)

19. Guided Practice 4
Use the quadratic formula to solve the equation: 2x2 – 3x – 6 = 0

20. Guided Practice 4
Use the quadratic formula to solve the equation: 2x2 – 3x – 6 = 0
Roots:
(2.64, 0)
(-1.13, 0)