You can use a program to display graphs on your TI-84 Plus calculator. In the program in this example, the PlotsOff command turns off all stat plots and the FnOff command turns off all functions in the Y= editor. The FnOn 1,2 command turns on the first two functions in the Y= editor so that only these two functions are graphed.
In order to store equations in Y1 and Y2, you must first put quotes around the expression you would like to graph, as shown in the first screen here.
The ZStandard command tells the calculator to graph these two functions in the standard viewing window where
as shown in the second screen of the figure.
Commands such as PlotsOff, FnOff, and ZStandard can be entered in your program from the Catalog menu.