Matrices on TI Calculators

On the TI-82 or TI-83
A. Entering a matrix:

1. On the home screen:

(a) Enter `[' to begin the matrix.
(b) Enter a second `[' to begin a row.
(c) Type in the numbers in the row separated by commas followed by a `]' to close the
row.
(d) Continue entering rows as above. Then enter `]' to indicate the end of the matrix.
(e) Press the STO and MATRIX keys.
(f) Select a name for your matrix and press ENTER .

2. Using the Matrix Editor:

(a) Press MATRIX .
(b) Select EDIT.
(c) Then scroll down to select a name for the matrix.
(d) Enter the appropriate number of rows and columns; followed by the entries in each
row.
(e) Use 2nd QUIT to return to the homescreen.

3. To display a matrix previously entered :
Press MATRIX , select the name of the matrix, and press ENTER twice.

B. Performing Elementary Row Operations :

1. Press MATRIX , then select MATH and scroll down to select the operation name and
press ENTER.

2. Press MATRIX, then scroll down to select a name for the matrix and press ENTER.

3. Complete the command line and press ENTER.

On the TI-85 or TI-86
A. Entering a matrix:

1. On the home screen:

(a) Enter `[' to begin the matrix.
(b) Enter a second `[' to begin a row.
(c) Type in the numbers in the row separated by commas followed by a `]' to close the
row.
(d) Continue entering rows as above. Then enter `]' to indicate the end of the matrix.
(e) Press the STO key followed by a letter, e.g., A, to name the matrix.

2. Using the matrix editor:

(a) Press MATRIX.
(b) Press 2nd Matrix to enter the matrix menu.
(c) Choose Edit
(d) Type in a letter, e.g., A, to name the matrix, followed by ENTER
(e) Change the row size and column size by entering the appropriate numbers, following
each by ENTER
(f) Then enter each of the matrix entries, pressing ENTER after each.
(g) After you finish, press EXIT

B. Performing Elementary Row Operations :

1. Press 2nd Matrix to enter the matrix menu.

2. Choose OPS

3. Choose from the following commands now available (you'll need to press MORE to see
some of them) using the indicated syntax:

• To interchange rows i and j in matrix A: rSwap(A,i,j)
• To multiply row i by scalar s in matrix A: multR(s,A,i)
• To replace row i by the sum of row i and s × (row j): mRAdd(s,A,j,i)
• To obtain the row echelon form of A: ref A
• To obtain the reduced row echelon form of A: rref A

On the TI-89, TI-92
A. Entering a matrix:

1. On the home screen:
Use the procedure described for the 85 & 86's.

2. Using the Matrix Editor:

(a) Press APPS and choose option 6, Data/Matrix Editor
(b) Select New
(c) For type, select matrix.
(d) Enter a letter to name the matrix; then key in the number of rows and columns.
(e) Press enter twice to obtain the matrix window.
(f) Then enter the matrix components.
(g) Press Home to exit the editor.

B. Performing Elementary Row Operations :
Press and Catalog and select the desired matrix operation, e.g., ref; rref, rowAdd, rowSwap,
mRow. Then enter the matrix or matrix name, and other characters as prompted.

C. Performing Other Matrix Operations :
Press 2nd and Math and select option 4 Matrix and select the desired matrix operation.