In Session 5, we learned that linear functions have constant first differences. That is, every time x increases by 1, y increases by a constant amount. In this section, we will come up with a description for another type of function: exponential functions. Note 2
Here's a table generated by a spreadsheet. The rule in the Output column is recursive: Start at 3 and add 10 each time. Here are the values in the table:
If you need a refresher on how to use a spreadsheet, see the tutorial in Session 5.
To generate this table in a spreadsheet using formulas, type the number "3" in cell B2, then type "=B2+10" in cell B3. Use the "Fill Down" menu command to continue the rule to cell B7.
Remember that the value in a cell is what is displayed, but the formula is used to generate the value. Click on cell B4 (the cell containing "23") to see the rule that generates the table: "=B3+10". You also could have used a formula to generate the values in column A.
Because the successive outputs have a constant difference of 10, these points should all lie on a line.