With the use of graphing calculators in the classroom, students can interactively discover the theory and technicalities behind equations and function graphing. Although graphing calculators can easily draw linear and inverse functions in terms of the X variable, oddly enough the functionality for graphing the X value in terms of the Y variable has been left out by graphing calculator developers. Fortunately, through the use of programmed scripts, you can add this functionality by uploading add-on applications to your calculator.

Click the TI Calc link in the Resources to download the X Graph program for the TI-84 Plus calculator on your computer. The downloaded file will be in a zipped file archive. Extract the contents of the Zip file by right-clicking the archive and selecting "Extract To" from the right-click menu. Extract the downloaded file to your computer's desktop.

Plug in your TI connectivity cable into your calculator and your computer's USB ports. Plug the jack connection into the top of your TI-84 Plus calculator, and insert the USB jack into your computer's port. Wait for your computer to detect your device and install the necessary drivers. When your device has been set up and is ready for use, a small box will pop up in the bottom right corner of your screen.

Click on the extracted program file you downloaded in Step 1. Press and hold the "Ctrl" key, then press "C" to copy the file.

Double-click on the "My Computer" icon on your computer's desktop space to open the windows file browser. Double-click on the TI-84 Plus calculator icon to open the contents of the calculator's memory.

Press and hold the "Ctrl" key, then press "V" to paste the downloaded file into your calculator's file directory. Disconnect your calculator when you see the file duplicated into your calculator's file directory.

Turn on your TI-84 Plus by pressing the "On" button. Press the "Apps" button to open a list of applications available to run on your calculator. Scroll down to the application titled "X Graph." Press the "Enter" key to open the application. An introduction splash screen will appear while the application initializes. When the program is loaded, you will see a list of "X=" open-ended equations on your screen.

Input your "X=" equations into the calculator. Type in as many equations as you need to graph. Inputting more than one equation will draw multiple lines when you execute the graph command. If you want to view only one equation at a time, simply input the a single equation into the first "X=" slot. Press the "X,T,Theta,n" key on your calculator to input a "Y" variable into your equation. Press the "Graph" button to draw the equation on your graph.