Example 4. Entering a formula into a spreadsheet.
We will set up the data that will allow us to graph the formula [latex]y=4+2{{(x-3)}^{2}}[/latex] on the values [latex]0\lex\le9[/latex].
- Set up the x-values from 0 to 20 as in the previous example, with the label x at the top of that column.
- Label the second column as y and then enter the following formula into the second cell in that column. The spaces aren’t needed. I show this with spaces only to make it easier to read.
=4+2*(A2–3)^2 (Enter) (It isn’t necessary to type capital letters for the cell locations. Excel will change them to capital letters automatically.) - Notice that after you punched Enter, the formula disappeared in the cell and was replaced by the value of the formula when [latex]x=0[/latex]. That’s because, in place of the x in the formula, you entered a cell location, so the spreadsheet used the value in that cell location and evaluated the formula. Did it evaluate the formula correctly? You should check it. Since [latex]y=4+2{{(x-3)}^{2}}=4+2{{(0-3)}^{2}}=4+18=22[/latex], the value for cell B2 should be 22. Is it?
- When you put your cursor on the cell where you typed the formula, which has a number in it now, notice that the formula itself appears in a line above the spreadsheet, so that you can still see it.
- Put the formula into the next cell. Copy the formula by highlighting the cell (left-click on the cell, then Edit>Copy.) Move the cursor to the next cell and then choose Edit>Paste. That should put the formula into the second cell. Notice that the second cell has a number, but the updated formula is in the line above the spreadsheet. How is the formula updated? Do you see that now it has the cell location A3 in it? So it’s using the next value for x, which is exactly what you want.
- Continue copying and pasting the formula until you have completed the spreadsheet. You can do that one cell at a time or you can copy into several cells at once by selecting several cells before you Paste. Experiment with this. Write notes about how to do it here.
A | B | |
---|---|---|
1 | x | y |
2 | 0 | 22 |
3 | 1 | 12 |
4 | 2 | 6 |
5 | 3 | 4 |
6 | 4 | 6 |
7 | 5 | 12 |
8 | 6 | 22 |
9 | 7 | 36 |
10 | 8 | 54 |
11 | 9 | 76 |