Texas Instruments TI-92 Getting Started page 30

Since the determinant of the matrix is not zero, it has an inverse matrix. Press A 2nd x
inverse. The result is shown in Figure 5.82.
Now let's solve a system of linear equations by matrix inversion. Once again consider
coefficient matrix for this system is the matrix
example. Now enter the matrix
6[Data/Matrix Editor] 2[Open]
to go to the matrix previously saved as b, which can be edited. Return to the Home screen (
–1
2nd x × B ENTER to get the answer as shown in Figure 5.83.
The solution is still x = 1, y = –l, and z = 2.
5.7.1 Iteration with the ANS key: The ANS key enables you to perform iteration, the process of evaluating a
function repeatedly. As an example, calculate
previous calculation. Continue to use each answer as n in the next calculation. Here are keystrokes to accomplish
this iteration on the TI-92 calculator. (See the results in Figure 5.84.) Notice that when you use ANS in place of n in
a formula, it is sufficient to press ENTER to continue an iteration.
3 0
Graphing Technology Guide: TI-92

1

− 
1

2

 
9
 
−  
as b. Since b was used before, when we stored 2a as b, press APPS
4
 
17
 
2[Matrix]
Figure 5.83: Solution matrix
5.7 Sequences
n −
1
for n = 27. Then calculate
3
Iteration Keystrokes
1 27 ENTER
(2nd ANS – 1) ÷ 3 ENTER
2
3 ENTER
4 ENTER
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−

2 3

which was entered as matrix a in the previous
3 0


−
5 5

and use to move the cursor to b, then press ENTER twice
8.666666667
2.555555556
.5185185185
–1
ENTER to calculate the
− + =

x 2 y 3 z 9

− + = −
x 3 y 4


− + =
2 x 5 y 5 z 17

HOME) and press A
n −
1
for n = the answer to the
3
Display
27
. The