1. 13.4 The Quadratic Formula Objective: 1.)To use the quadratic formula to solve quadratic equations 2.) To use the discriminant to find the number of solutions for a quadratic equation

2. Quadratic Formula The boy with the negative attitude couldn’t decide whether to go to the radical party or b² and miss out on the 4 awesome chicks the party is over at 2am

3. Quadratic Song to Pop Goes the Weasel x equals negative b Plus or minus the square root Of b squared minus four a c All over 2a

4. Video Time

5. Example 1:3x 2 – 9x + 1 = 0

6. Ex 2: 2x 2 = 4 – 7x 2x 2 + 7x – 4 = 0

7. Ex 3: Solve: 3x 2 – 4x - 2 = 0

8. Ex :4 Solve: x 2 - 4x - 7 = 0

9. Discriminant Determines the number of real-number solutions of a quadratic equation b² - 4ac = discriminant

10. Discriminant of a Quadratic 3 possibilities b²-4ac 1.) If positive then 2 solutions for x 2.) If 0 then 1 solution for x 3.) If negative then no real solutions for x

11. Ex 5: How many solutions? 3x 2 – 5x + 1 = 0 “discriminate” Negative: no solution Zero: one solution Positive: two solutions 2 solutions

12. Ex 6: How many solutions? y = x 2 – 3x + 7 = 0 “discriminate” Negative: no solution Zero: one solution Positive: two solutions 0 solutions

13. Ex: 7How many solutions? f(x) = x 2 – 12x + 36 = 0 “discriminate” Negative: no solution Zero: one solution Positive: two solutions 1 solutions

14. Assignment: Page 593 # 2-28, 42-52 finding the roots is the same as solving for x