I. Graphing a function on the TI-86:

A. Easy graph, tracing and evaluating

1. Press the 'ON' button, located at the bottom left corner of the calculator.
2. Press the 'GRAPH' button which is on the leftside, third button down.
3. Press the F1 button, located at the top left corner of the calculator. It will access whatever is at the bottom of the screen, which right now is 'y(x)='.
4. Type in a function, like x² , in the spot where it says '\y1='.
5. We want the ZOOM menu, which you'll notice is on the second layer of choices on the screen.  So, press the yellow '2nd' button, then press F3 (which will give us the second layer!)
6. You'll see a list of options;  the fourth one over is 'ZSTD', which gives us a 10 by 10 graphing window, with (0,0) at the center.  Press F4 now!
7. While viewing the graph, press the  F4 button just below the word 'TRACE' at the bottom of the screen. After doing that, you may press the right/left arrows to get the x- and y-coordinates of the blinking dot. (Do it!)
8. You may get the x- and y-coordinate of any single point that you want by using the calculator's built-in 'value':
   • At the bottom of the screen you see a bunch of options. At the end of the screen is a little arrow telling you there are more options. Find the button with the word 'MORE' on it, and press it!
   • Still more options, so press 'MORE' again.
   • This time, one of the options is 'EVAL'; press the button below it, which happens to be F1.
   • At the bottom of the screen you will see 'X = '. Type in any x-value, then press 'ENTER'.

B. Choosing a window

1. After entering your function, you could pick the graphing window you want, by hand. Press button F2, just below the letters 'WIND' (for window).
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 F5 button below the word 'GRAPH' that's in the top row, furthest button to the right.

C. Other zoom option summaries:

• ZIN and ZOUT: 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. ZIN gives you a much more detailed view of a smaller part of the graph, while ZOUT gives you a better view of the big picture, with less detail.
• ZBOX: 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.
• ZFIT: 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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