Calculator Basics for the TI-83 and -84

Max and Min

• Max:  Enter the function to graph in  Y= . Make sure the window is properly adjusted so you can see the maximum. Then, select  2nd CALC (above the  TRACE  button), followed by  4:maximum . Now follow the directions at the bottom of the screen. Cursor to the left of the maximum and hit enter. Cursor to the right and hit enter. Cursor to a rough guess at the max and hit enter. (These three steps follow the calculator prompts.) The calculator should pause for a moment, then give the x- and y- coordinate of the maximum point at the bottom of the screen.
• Min:  The same as above, except select  3:minimum .

Intersections

• Intersections:  Enter the two functions you want to find the intersection of in  Y= . Make sure the window is adjusted so you can see the intersection. Select  2nd CALC  and then  5:intersect . If the only graphs are those you want to find the intersection of, just hit enter twice. Then cursor over to a rough guess of the intersection and hit enter. The calculator will pause, then give the coordinates of the intersection.

Window and Zoom

• Adjusting Window Values:  Once you have entered the function in  Y= , graph in the standard window. If you can't see the entire graph, hit  WINDOW .  Xmin  and  Xmax  are the lowest and highest values graphed on the x-axis. Adjust them as necessary. Similarly,  Ymin  and  Ymax are the lowest and highest values graphed on the y-axis. Several adjustments may be necessary before you can see the whole graph.
• Zoom Standard: Pressing Zoom followed by 6:ZStandard returns your window to -10 to 10 in both the x and y directions.
• Zoom Stat: Pressing Zoom followed by 9:ZoomStat is useful when graphing data points.
• Zoom Trig: Pressing Zoom followed by 7:ZTrig sets your window to -2pi to 2pi in the x direction with tick marks every pi/2 units, and -4 to 4 in the y direction with tick marks every 1 unit.
• Zoom Fit: Selecting ZoomFit keeps your XMin and XMax, but recalculates the YMin and YMax to include the min and max y-values that correspond to your chosen x-interval.
• Zoom Box:  If there is one tiny piece of a graph that you would like to see more of, you can use ZoomBox. Hit  ZOOM , and then select 1:ZBox . A blinking cursor will appear on the screen along with the graph. Think about the piece of graph you'd like to box in, and place the cursor at one corner of the box. Hit enter. Use the arrow keys to move the cursor until a little box is formed around what you want to see. Hit enter again, and the screen will automatically resize to show you the piece of the graph inside the little box.

Graphing Piecewise-Defined Functions

This is probably best done by hand, but the calculators can do it. The only thing they can't do is tell you whether endpoints are open or closed. Here is an example of the syntax:  y1=(x+4)(-4 x)(x 7)+(-x)(x>7) . The inequality symbols are found under Test, which is  2nd MATH .