I. Graphing a function on the TI-89:

Two important notes about the TI-89 buttons:

• To access any of the commands in green printed above the buttons, you need to press the green 'diamond' button first. It is located on the bottom row next to the 'ON' button.
• To access any of the commands in yellow printed above the buttons, you need to press the yellow '2nd' button first. It is located on the bottom row next to the green button!

A. Easy graph, tracing and evaluating

1. Press the 'ON' button, located at the bottom left corner of the calculator.
2. Press the green button, then the F1 button way at the top (so we're accessing the 'Y=' command.)
3. In any empty spot, say y1=, type an expression you want to graph, like x².
4. Press the F2 button,  located way to the left with all of the other F buttons. You should see a big list of ZOOM options.
5. The sixth one down is 'ZOOMSTD', which gives us a 10 by 10 graphing window, with (0,0) at the center.  We can access this either by using the arrow buttons (which are located on the big round thing in the upper left hand corner of the calculator) to slide down to it and press ENTER, or by just pressing the number 6.
6. Look at the top of the screen; you'll see what is called a toolbar. (The toolbar box with Zoom in it is F2). The toolbar box with 'TRACE' in it says F3. So press F3, and at the bottom of the screen you'll see the x- and y-coordinates of the point that's blinking on the graph. Using the left and right arrows now moves the blinking dot along the graph, while the x- and y-coordinates change accordingly.
7. You may get the x- and y-coordinate of any single point that you want by using the calculator's built-in 'value':
   • Notice that toolbar box 'MATH' says F5. Press F5 and you'll get a long list of math things you can do; at the moment we want 'VALUE', which is item 1 on the list. Choose it!
   • At the bottom of the screen, you'll now see 'x ='. Type in any x-value, then press either of the two 'ENTER' buttons.

B. Choosing a window

1. After entering your function, you could pick the graphing window you want, by hand. Press the green diamond button, then the F2 button way at the top (so we're accessing the command 'WINDOW' above it!)
2. In the list of things you see, 'XMIN' is the furthest left you want your graph to go, 'XMAX' is the furthest right you want the graph to go, 'YMIN' is the lowest you want the graph to go, and 'YMAX' is the highest you want the graph to go. Let's change each to the following, by going to each item using the up/down arrows:
   • XMIN = -2
   • XMAX = 5
   • YMIN = -1
   • YMAX = 30.
3. Don't go to the ZOOM menu! Just press the green diamond button, then the F3 button way at the top (which means we're accessing the green 'GRAPH' command just above it!)

C. Other zoom option summaries:  When you press F2, you'll see a big list of other ZOOM options. Here are the most important ones.

• ZoomIN and ZoomOUT: These stand for Zooming In and Zooming Out.  For both of these, you go to the ZOOM menu, and choose it. Move the cursor to where you want to be the new center of the screen, then press ENTER. ZoomIN gives you a much more detailed view of a smaller part of the graph, while ZoomOUT gives you a better view of the big picture, with less detail.
• ZoomBOX: To use Zoom Box, choose it in the Zoom menu. Then go to the graph, and put the cursor where you want a corner of your box to be. Press ENTER. Now pressing the up/down/left/right arrows starts to draw a box for you. When you have the box in just the right position, press ENTER, and only points in the box you picked will be graphed.
• ZoomFIT: First, go the WINDOW and pick whatever you want XMIN and XMAX to be (so you have chosen the left and right sides of the window.) Pressing ZFIT now gets the calculator to calculate all the points BEFORE it starts graphing. It then adjusts the screen so that the top of the screen is the highest y-value calculated, and the bottom of the screen is the lowest y-value calculated.

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