The basic functions of the TI-89 are clear, because you can see them directly on the arrangement of buttons on the calculator itself. What may not be clear is that the TI-89 also has strong matrix capabilities. Entering matrices on the TI-89 is not a particularly difficult affair, because the TI-89 offers an application that is similar to a spreadsheet program, allowing you to enter matrices in a visual manner.
Enter the matrix editor. Press the “apps” button on the TI-89. A selection screen will appear. Choose “data/matrix editor” to open the matrix editor.
Create a new matrix. Press “3.” This action will bring up a menu with the title “new.” In this menu, there are three boxes that you must fill in. For “variable,” choose any letter that you want the numbers in the matrix to represent. For “row dimension,” enter the number of desired rows for your matrix. For “col dimension” enter the number of desired columns for your matrix. For example, if you want a matrix that represents values for the variable “x” and is 2 by 4 (composed of 2 rows and 4 columns), enter “x,” “2” and “4” for “variable,” “row dimension” and “col dimension,” respectively.
Enter the data for the matrix. Hit “enter” to go to the spreadsheet-like data editor. An empty matrix with the desired rows and columns will be waiting. Use the arrow keys to move between cells, and use the number keys to enter values for those cells. When finished, hit “enter” to finalize and display your matrix.