# Matrix Operations Method :
1) Hit the MATRX key and use the arrows to highlight EDIT. Since matrix [A] is already
highlighted, you can just press ENTER . 2) You are now ready to enter matrix A into your calculator. First you need to tell the calculator
the size of matrix A. Press 3 for the row size, then ENTER. Press 3 for the column size then
ENTER. The calculator now displays a 3 by 3 matrix. 3) Type each entry in the matrix going across rows. Press ENTER after each entry. If there are
already numbers in the matrix , you can just type the new numbers over the old. 4) Verify that you typed each entry correctly. If a mistake was made, use your arrow keys to go
to the correct location and change the entry . Press 2nd QUIT to exit the Matrix editor.

5) Enter matrices B and C into your calculator. You will need to begin with Step 1 each time ,
selecting [B] and [C].  Method :

1) Make sure you are on the Home screen of your calculator. Press 2nd QUIT if you are not
sure.

2) Press MATRX and note that NAMES and 1: are highlighted. Press ENTER to select Matrix A 3) Press +. 4) Press MATRX. Use the down arrow to highlight Matrix B. Once it is highlighted, press 5) Press ENTER and the calculator will perform the addition. 6) Try adding matrix B to matrix C. You should get a dimension mismatch error. Matrices must
be the same size in order to add or subtract them. Task: Multiply a matrix by a scalar: Method:

1) On your home screen type -7 *.

2) Press MATRX. Use the down arrow to highlight matrix C. Once it is highlighted, press 3) Press ENTER and the calculator will perform the multiplication. Method:

1) Be sure you are on the Home screen. Press MATRX. Use the down arrow to highlight matrix
B. Once it is highlighted, press ENTER to select matrix B and return to your home screen.

2) Press *

3) Press MATRX. Use the down arrow to highlight matrix C. Once it is highlighted, press

4) Press ENTER and the calculator will perform the multiplication. 5) Try multiplying matrix C * matrix B. You should get a dimension mismatch error. The
number of columns of the first matrix, must match the number of rows of the second matrix.

Task: Determine the inverse of a matrix: Method:

1) Be sure you are on the Home screen. Press MATRX. Verify that matrix A is highlighted. Once

2) Press the inverse key on your calculator: x-1

3) Press ENTER to have the calculator determine the inverse. 4) You may want to change the results to fractions by pressing MATH; highlighting Frac and
then pressing ENTER. 5) If you try to determine the inverse of matrix C, you will get an invalid dimension error. Only
square matrices have inverses.

Task: Determine the determinant of a matrix
Method:

1) The determinant function is part of the matrix math menu . Press 2nd MATRX and use the
right arrow to go over to the MATH menu. The first command is for determinant. 2) To calculate the determinant of Matrix A, press ENTER to select item 1. You will now
be brought back to the home screen. Now select Matrix A by pressing 2nd MATRX and
from the NAMES menu selecting [A]. Again you will be returned to the home screen. 3) Close the parentheses and press ENTER to get the value of the determinant . Prev Next