After this exploration, you should be able to:

generate a table of values

You have already learned how to graph a line, let's extend this concept to quadratic functions.

Let's begin by evaluating quadratic functions to generate a table of possible values

EVALUATE MEANS "TO FIND THE VALUE OF"

Find 4 values of the function

If x = 1, then

If x = 2, then

If x = 3, then

If x = 4, then

 x values function values 1 1 2 4 3 9 4 16

Now let's use Microsoft Excel to evaluate and graph this function

Instructions:

Steps 1-7 show you how to evaluate a quadratic function using Excel, and steps 8- allow you to graph a quadratic function from the data.

1. Open the program Microsoft Excel.

2. Type "x values" in cell A1. Type "f(x) = x^2" in cell B1.

3. In cell A2, type "-10". Then press return.

4. In cell A3, type "=A2 +1". Then press return.

5. Click on cell A3. At the bottom right corner of the cell, drag the thin solid black cross (which changes from the white cross) down to cell A22. You should see the following:

 x values -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10

6. In cell B2, type "=(A2)^2"

7. Click on cell B2. At the bottom right corner of the cell, drag the solid black cross down to cell B22.

 100 81 64 49 36 25 16 9 4 1 0 1 4 9 16 25 36 49 64 81 100

8. To graph this data, we must highlight all of the cells from A2 to B22 by clicking on A1 and dragging to B22 until all of the cells are black.

9. Click the Chart Wizard icon or go to the menu bar and select "Insert" then "Chart".

10. This opens the chart wizard options. For Chart type: Select X-Y Scatter. Press return at the first graph icon.

11. Follow the prompts for entering data labels and titles. For a title type in "Quadratic Function"; for the x-axis label use "x values"; and for the y-axis label use " function values" . It should look like this graph below.