Edit, Display, and Augment Matrices on the TI83 Plus
After you have defined matrices on the TI83 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 realnumber entries.
Edit a matrix on the TI83 Plus
To edit an alreadydefined matrix, follow these steps:

Press
to enter the Matrix editor menu. On the TI83, press
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.

Key in the number (1 through 9, or 0) of the matrix you want to define or redefine.
If you select an alreadydefined 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 alreadydefined matrices on your PC.

Use the
to place the cursor on the entry to be edited.

Key in the new number and press [ENTER].

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 TI83 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 TI83, press [MATRX].) Finally, press [ENTER] to display the matrix. If the Home screen isn’t large enough to contain the whole matrix, use the
keys to view the missing elements.
Augment two matrices on the TI83 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:

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

Press
to select the augment command from the Matrix Math menu.

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.

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

Store the augmented matrix under a specified matrix name.
To do so press
enter the name of the matrix in which you plan to store the augmented matrix, and then press [ENTER].