Texas Instruments TI-82 Keystroke Manual page 57

52 Calculator Keystroke Guide
2 and press ENTER. The calculator now displays a
two columns, as shown on the right below.
Notice that the cursor is now positioned on the number in upper left corner of the matrix. This
position is row 1, column 1, in the matrix. The calculator displays
screen to indicate that the number presently in the position row 1, column 1, is 0. Referring to
matrix A for our system of equations, the number in row 1, column 1, needs to be 2. Type a 2. At
the bottom of the screen the display now reads
above has not yet changed. Press ENTER to have the calculator enter 2 into the position row 1,
column 1, of the matrix.
Before Pressing ENTER
The cursor is now highlighting the number in the position row 1, column 2. At the bottom of
the screen the display reads
system of equations the number in matrix A in the position row 1, column 2, is supposed to be −4,
so type a −4 and press ENTER to enter it into that position in the matrix. The cursor moves to
position row 2, column 1, as shown on the left below, where a 3 is supposed to appear in our
matrix A. Continue to enter the rest of the numbers into matrix A so that it looks like the figure on
the right below. If you make a mistake, just use the arrow keys to highlight the number you wish
to change, type in the correction, and press ENTER.
To enter the matrix B for our system of equations, press MATRX. (Notice that on the MATRX
screens the matrix A now has the notation
=2, but the highlighted number in the matrix
,
1 1
After Pressing ENTER
=0, which indicates that the number in this position is 0. For our
,
1 2
2 ×
2 next to it to denote that a matrix with two rows
2 ×
2 matrix, that is, one with two rows and
=0 at the bottom of the
,
1 1