Edit, Display, and Augment Matrices on the TI-83 Plus

By C. C. Edwards

After you have defined matrices on the TI-83 Plus graphing calculator, you might need to edit them, display them on the Home screen, or append one matrix to another. The calculator allows you to define up to ten matrices. Each matrix can have dimensions of up to 99 X 99 and can contain only real-number entries.

Edit a matrix on the TI-83 Plus

To edit an already-defined matrix, follow these steps:

  1. Press

    Three buttons in the TI-83 graphing calculator.

    to enter the Matrix editor menu. On the TI-83, press

    Instructions to enter the matrix editor on the TI-83 calculator

    The dimensions appearing to the right of the first two matrices indicate that these two matrices have already been defined and are stored in the memory of the calculator.

  2. Key in the number (1 through 9, or 0) of the matrix you want to define or redefine.

    If you select an already-defined matrix, the following steps redefine that matrix by overwriting any existing entries. The redefined matrix replaces the original matrix in the memory of the calculator.

    If all ten matrices in the Matrix editor are defined and you don’t want to sacrifice any of them in order to define a new matrix, consider saving some of the already-defined matrices on your PC.

  3. Use the

    The arrow keys in a TI-83 calculator.

    to place the cursor on the entry to be edited.

  4. Key in the new number and press [ENTER].

  5. When you’re finished editing your matrix, press [2nd][MODE] to exit (quit) the Matrix editor and return to the Home screen.

Display matrices on the TI-83 Plus

To display a matrix on the Home screen, first press [2nd][MODE] to access the Home screen. Then press [2nd][x–1] and enter the number of the matrix to be displayed. (On the TI-83, press [MATRX].) Finally, press [ENTER] to display the matrix. If the Home screen isn’t large enough to contain the whole matrix, use the

Up, Right, Down, and left arrows on the TI-83 calculator.

keys to view the missing elements.

Augment two matrices on the TI-83 Plus

Augmenting two matrices allows you to append one matrix to another matrix. Both matrices must be defined and have the same number of rows. To augment two matrices, follow these steps:

  1. If necessary, press [2nd][MODE] to access the Home screen.

  2. Press

    Buttons you must press to augment two matrices on the TI-83 Plus

    to select the augment command from the Matrix Math menu.

  3. Enter the name of the first matrix and then press [,].

    The first matrix is the matrix that appears on the left in the augmented matrix. To enter its name, press [2nd][x–1] and key in the number of the matrix name.

  4. Enter the name of the second matrix and then press [ ) ].

  5. Store the augmented matrix under a specified matrix name.

    To do so press

    The Store command button on a TI-83 calculator

    enter the name of the matrix in which you plan to store the augmented matrix, and then press [ENTER].

    Three stored matrices on the TI-83 plus.