After you’ve entered functions in the Y= editor of your TI-84 Plus calculator, you can have the calculator create a table of functional values. The table values are automatically color-coded to match the color of the functions on the graph. There are two kinds of tables you can create: an automatically generated table and a user-generated table.
Automatically generated tables with the TI-84 Plus
To automatically generate a table, perform the following steps:
Highlight the equal sign of those functions in the Y= editor that you want to appear in the table.
Only those functions in the Y= editor that are defined with a highlighted equal sign appear in the table. To highlight or remove the highlight from an equal sign, press [Y=], use the arrow keys to place the cursor on the equal sign in the definition of the function, and then press [ENTER] to toggle the equal sign between highlighted and not highlighted. See the first screen.
Press [2nd][WINDOW] to access the Table Setup editor.
Enter a number in TblStart, and then press [ENTER].
TblStart is the first value of the independent variable x to appear in the table. In the second screen, TblStart is assigned the value 5.
To enter the number you have chosen for TblStart, place the cursor on the number appearing after the equal sign, press the number keys to enter your new number, and then press [ENTER].
Enter a number in
and then press [ENTER].
gives the increment for the independent variable x. In the second screen the value –1 is assigned.
To enter the number you have chosen, place the cursor on the number appearing after the equal sign, press the number keys to enter your new number, and then press [ENTER].
Press [2nd][GRAPH] to display the table.
See the third screen. Here’s what you see and what you can do with an automatically generated table:
If Indpnt and Depend are both in Auto mode, then when you press [2nd][GRAPH], the table is automatically generated. To display rows in the table beyond the last row on the screen, repeatedly press the down-arrow key until they appear. You can repeatedly press the up-arrow key to display rows above the first row on the screen.
Notice the Context Help message in the border at the top of the third screen. If the TableStep is not to your liking, press [+], enter your new TableStep, and press [ENTER].
If you’re constructing a table for more than four functions, only the first four functions appear on the screen. To see the other functions, repeatedly press the right-arrow key until they appear. This causes one or more of the initial functions to disappear. To see them again, repeatedly press the left-arrow key until they appear.
Each time the calculator redisplays a table with a different set of rows, it also automatically resets TblStart to the value of x that appears in the first row of the newly displayed table. To return the table to its original state, press [2nd][WINDOW] to access the Table Setup editor, and then change the value that the calculator assigned to TblStart.
User-generated tables on your TI-84 Plus
To create a user-generated table, perform the following steps:
Press [2nd][WINDOW] to access the Table Setup editor.
Set the mode for Indpnt and Depend.
To change the mode of either Indpnt or Depend, use the arrow keys to place the cursor on the desired mode, either Auto or Ask, and then press [ENTER].
Press [2nd][GRAPH] to display the table.
When you display the table, it should be empty. If it’s not empty, clear the table.
In an empty table, key in the first value of the independent variable x that you want to appear in the table, as shown in the second screen. Press [ENTER] and the corresponding y-values of the functions in the table automatically appear. Key in the next value of x you want in the table and press [ENTER], and so on.
The values of x that you place in the first column of the table don’t have to be in any specific order, nor do they have to be between the Xmin and Xmax settings in the Window editor!
For a user-defined table, you don’t have to assign values to TblStart and ΔTbl in the Table Setup editor.
The other combinations of mode settings for Indpnt and Depend are not all that useful, unless you want to play a quick round of “Guess the y-coordinate.”
The word ERROR appearing in a table doesn’t indicate that the creator of the table has done something wrong. It indicates that either the function is undefined or the corresponding value of x is not a real-valued number. This is illustrated in the third screen.