How to Start and Quit Inequality Graphing on the TI-84 Plus
With the Inequality Graphing application that comes preloaded on the TI-84 Plus family of graphing calculators, you can graph functions and inequalities. You can even graph and shade regions formed by the union or intersection of several inequalities. You can also use this application to solve linear programming problems.
How to start Inequality Graphing on the TI-84 Plus
To start the Inequality Graphing application, press [APPS][ALPHA][x2]; if necessary, use
to move the cursor to the Inequalz application, and press [ENTER] to select the application. You are confronted with one of these three screens.
If no other applications are running, you see the first screen. Press any key to enter the Inequality Graphing application. If Inequality Graphing is already running, you see the second screen. Press  to re-enter the application. The third screen tells you that another application is currently running. Press  to exit that application, and then press any key to enter Inequality Graphing.
After you enter Inequality Graphing, you are placed in the Y= editor so that you can enter functions and inequalities. The functions previously housed in this editor appear on the screen along with the inequality symbols at the bottom of the screen, as illustrated in the first image here. If you move the cursor so that it is not on an equal sign, the inequality symbols at the bottom of the screen vanish, as in the second image.
How to exit Inequality Graphing on the TI-84 Plus
Most of the time you don’t even know the Inequality Graphing application is running unless you are actively using the application or unless you place the cursor on an equal sign in the Y= editor to display the inequality symbols. How to quit the application is about as puzzling as knowing whether or not it is running.
To quit (exit) this application, press [APPS][ALPHA][x2]; if necessary use
to move the cursor to the Inequalz application, and press [ENTER] to select the application. When you see the second screen, press  to quit the application.