1. Warm-Up 5 minutes Solve by completing the square. 1) x2 – 10x + 23 = 0

2. Mastery is 80% or better on 5-min check and Indy work.
The Quadratic Formula
Objectives:
Students will use the quadratic formula to solve quadratic equations. Determine the number of solutions by utilizing the discriminant.
Mastery is 80% or better on 5-min check and Indy work.

3. Concept Dev-The Quadratic Formula
If ax2 + bx + c = 0, a = 0, then the quadratic formula
gives the solutions of the quadratic equation.

4. Skill Dev-Example 1 Solve using the quadratic formula.
3x2 – 7x + 2 = 0

5. Example 1
Solve using the quadratic formula.
3x2 – 7x + 2 = 0

6. Skill Dev- Example 2 Solve using the quadratic formula.
-x2 + x + 1 = 0

7. Example 2
Solve using the quadratic formula.
-x2 + x + 1 = 0

8. Guided-Practice…Boards
Solve using the quadratic formula.
Approximate the solutions to the nearest tenth.
1) 2x2 – 4x = 5
2) x2 + 5x = -3

9. Guided- Practice
Use the quadratic formula to find the roots of each polynomial.
1) 6x2 – 6 – 5x
2) 6x2 – 6x - 5

10. Homework
HW PDF Online
Quad Formula & Disc

11. Warm-Up 5 minutes Solve using the quadratic formula. 1) x2 = 8x - 16

12. To use the quadratic formula to solve quadratic equations
Objectives:
To use the quadratic formula to solve quadratic equations
To use the discriminant to find the number of solutions for a quadratic equation

13. The Discriminant
The expression under the radical, b2 – 4ac, is called the discriminant.
We can use the discriminant to determine the number of solutions
b2 – 4ac is positive: two real number solutions
b2 – 4ac is zero: one real number solution
b2 – 4ac is negative: no real number solutions

14. Skill Dev - Example 1
Determine the number of real solutions, then solve using the quadratic formula.
4x2 – 7x + 2 = 0
b2 – 4ac = 49 – (4)(4)(2)
b2 – 4ac = 17
two real solutions

15. Guided - Practice
Determine the number of real solutions, then solve using the quadratic formula.
1) x2 + 5x = -8
2) 4x2 = 8x - 4
3) 4x2 + 4x = 15

16. Think..Ink..Share Practice
Use the discriminant to determine whether the graph of each quadratic function intersects the x-axis in 0,1, or 2 points.
1) y = 3x2 - 5x + 1
2) f(x) = x2 – 3x + 7
3) y = x2 – 12x + 36

17. What did you learn?
Students will use the quadratic formula to solve quadratic equations. Determine the number of solutions by utilizing the discriminant.
Mastery is 80% or better on 5-min check and Indy work.