1. 6.2 Solving Quadratic Equations by Graphing
Estimate solutions of quadratic equations by using a table.

2. Quadratic equation
A Quadratic function set to a value is called a Quadratic equation.
The solutions for x are called roots or zeros.

3. Find the Roots of the equation
Find the x value of the vertex to start your table.

4. Make a Table. Start with 1.5 (x, y) (1.5,- 6.25 ) (1.5)2 – 3(1.5) – 4
(1.5, ) (1.5)2 – 3(1.5) – 4
2.25 – 4.5 – 4 = -6.25
(1,- 6) 12 – 3(1) – 4
(2,- 6) 22 – 3(2) – 4= -6
(0,- 4)
(3,- 4) 32 – 3(3) – 4 = -4
(-1, 0) (-1)2 – 3(-1) – 4 = 0
( 4, 0) 42 – 3(4) – 4=0
Roots ( - 1, 0) , (4, 0)

5. Quadratic equations have either 2, 1 or 0 solutions
2 solutions, where the parabola hits the x axis two times.

6. Quadratic equations have either 2, 1 or 0 solutions
1 solutions, where the parabola hits the x axis one time.
If the
Vertex is
On the
Graph it
Has only
one root

7. Quadratic equations have either 2, 1 or 0 solutions
No solutions, where the parabola does not hits the x axis.

8. How do I find the roots of a quadratic equation with a table
The graph of the quadratic: Must be given of find a table

9. How do I find the roots of a quadratic equation with a table
The graph of the quadratic Given Table

10. How do I find the roots of a quadratic equation with a table
The graph of the quadratic Table
Between -3 and -2
2 and 3
is a zero, why?

11. Homework
Page
# 15 – 37 odd,
38,41

12. Homework
Page 298
# 20 – 36 even