After this exploration, you
should be able to:
generate a table of values
evaluate quadratic equations
graph quadratic functions using
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
Given the following quadratic
Find 4 values of the function
If x = 1, then
If x = 2, then
If x = 3, then
If x = 4, then
Now let's use Microsoft Excel
to evaluate and graph this function
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
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:
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.
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.
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