1. 9.6 THE QUADRATIC FORMULA:
Quadratic Formula: Formula used to find the solution(s) of any quadratic equation.
If ax2+bx+c = 0 and a ≠ 0, then

2. GOAL:

3. x2-8=2x QUADRATIC EQUATION:
Ex: What are the solutions to? Use the quadratic formula.
x2-8=2x

4. x2-8=2x  x2-2x-8 =0 x = -2, 4 SOLUTION:  a = 1 , b = -2 and c = -8
We must first put the equation in ax2+bx+c=0 form.
x2-8=2x
 x2-2x-8 =0
 a = 1 , b = -2 and c = -8
x = -2, 4

5. YOU TRY IT:
Ex: What are the solutions to? Use the quadratic formula.
x2-4x=21

6. x2-4x=21  x2-4x-21 =0 x = -3, 7 SOLUTION:
We must first put the equation in ax2+bx+c=0 form.
x2-4x=21
 x2-4x-21 =0
 a = 1 , b = -4 and c = -21
x = -3, 7

7. REAL-WORLD: In the shot put, An athlete throws A heave metal ball
Through the air. The arc of the ball is modeled by the equation: -0.04x2+.84x+2. Where x is the horizontal distance. How far from the athlete will the ball land?

8. x cannot be negative: x = 23.16 meters
SOLUTION:
The given equation is already in standard form:
-0.04x2+0.84x+2 = 0
 a = , b = and c = 2
x cannot be negative: x = meters

9. VIDEOS: SOLVING BY FACTORING Solving by factoring:

10. VIDEOS: SOLVING BY FACTORING Solving by factoring:

11. CLASSWORK: Page :
Problems: 4, 7, 15, 21, , 36, 37.