About Using the TI 89 for Calculus
The TI 89 comes in two different models: the Titanium and the “regular.” There is very little difference between the two; The color-coding is slightly different and the Titanium has a few features that the basic model does not — like twice the flash memory and the ability to connect to your computer via a GraphLink cable. These small features make very little difference in following the guides. When you turn your calculator on, you’ll enter the HOME screen. You can do some calculations on this screen (type your entry straight into the command line) and the solutions will appear in the center of the screen. For the most part, you’ll be using the function keys at the top of the screen or the APPS (applications) button.
Perhaps the two most important buttons are the HOME keys and ESC keys. These will get you out of many sticky situations; if you get lost in a nest of applications screens, the home button will return you to the home screen. If you enter an application and decide not to go further (or if you hit the wrong key), the ESC button will back out of the menu. You can also use the ESC key if you enter data but decide not to save it. Other useful keys:
- F6 2:New Problem will ease all variables named by a single letter. This comes in handy if you’re working on problem sets and want to briefly work some problems.
- The CATALOG key brings up a list of all available commands and functions. If you can’t find what you’re looking for in the myriad of menus and sub-menus, check the catalog. For example, you can find a factorial (!) here, which isn’t found in any of the functions or menus.
A couple of tips:
- Variable names must start with a letter (for example, L1 for “list one”) and they can be up to 8 characters long.
- Use implied multiplication on the home screen (e.g., x*y instead of xy). This makes sure the TI-89 doesn’t interpret xy as a new variable name.
- Graphing and Tables:
- Other Topics
The TI-89 guesses at what portion of the graph you want to see. Usually, you’ll have to tweak the viewing window to get a useful result. The TI-89 has several features to change the viewing window, including ZoomIn, Zoomout and ZoomStd — which displays the “standard” window from -10 to 10. ZoomBox allows you to box in a certain area of the graph and then zoom in on that portion.
Sample problem: Magnify the graph of the following function using ZoomBox feature:f(x) = 10 sin(x)
Step 1: Press HOME.
Step 2: Press the DIAMOND key and then F1 to enter the y=editor.
Step 3: Type the function into the in the “y1 =” slot of the y=editor. To enter the function, press ENTER to move down to the input line and then press 10 2ND Y x ).
Step 4: Press ENTER.
Step 5: Press the DIAMOND key and then F3 to view the graph of the function. If you can’t see the graph on your screen, set your window to display the graph. For this particular graph, you’ll be able to see the graph with the ZoomStd feature; Press F2 and then press 6.
Step 6: Press F2 and then 1 to access the ZoomBox feature.
Step 7: Select the first corner of the box by pressing the arrow keys. Press ENTER.
Step 8: Select the second corner of the box. Press ENTER.
That’s it! You’re done!