Student Activity: Factoring Quadratics By Graphing (Page 4 of 4) in pdf

Student Activity: Factoring Quadratics By Graphing Page 4

Calculator Notes

1. Turn on the calculator, go to the GRAPH Menu and

press EXE. The screen should look like the one on

the right.

2. To make sure that the View Window in set up for

graphing the equations, press Shift F3 and F3

again. Then press EXE. The calculator is ready to

graph the equations. The screen at the right shows

the equation y = x

- 8x + 15 being graphed.

3. To find the roots of this equation, press Shift F5

and F1. The calculator will display the lefthand root

first as shown on the screen to the right. One of the

roots is x = 3 and the factor would be (x - 3). To get

to the other root, press the Right Arrow key.

4. In some cases, due to pixel resolution, the root will

not be found using Root in the G-Solve Function.

This happens when the quadratic is a perfect square

involving a fraction. The screen at the right shows

what happens when you try to find the root for the

equation y = x

x +

5. Since the equation above opens upwards, it has a

minimum value. Use G-Solve and F3 to find the

minimum value. This will give you the roots as shown

in the screen to the right. The value of x can be

rounded to get x = .8 and the root would be (x - .8)

which is (x -

) as a fraction.

Student Activity: Factoring Quadratics By Graphing Page 4