Texas Instruments TI-92 Getting Started page 29

Row Operations
add row 1 to row 2
add –2 times row 1 to row 3
add row 2 to row 3
multiply row 3 by
Thus z = 2, so y = –1, and x = 1.
Technology Tip: The TI-92 can produce a row-echelon form and the reduced row-echelon form of a matrix. The
row-echelon form of matrix a is obtained by pressing 2nd MATH 4[Matrix] 3[ref(] A) ENTER and the reduced
row-echelon form is obtained by pressing 2nd MATH 4[Matrix] 4[rref(] A) ENTER. Note that the row-echelon
form of a matrix is not unique, so your calculator may not get exactly the same matrix as you do by using row
operations. However, the matrix that the TI-92 produces will result in the same solution to the system.
5.6.4 Determinants and Inverses: Enter this 3×3 square matrix as a:
three columns of the matrix a that was previously used, you can go to the matrix, move the cursor into the fourth
column and press F6[Util] 2[Delete] 3[column]. This will delete the column that the cursor is in. To calculate its
−
 1 2 3 
 
− 
determinant 1 3 0

 
−
2 5 5
 
find that the determinant is 2 as shown in Figure 5.81.
Figure 5.81: Determinant of a
2 9
Graphing Technology Guide: TI-92
1
2
Figure 5.80: Final matrix after row operations
, go to the Home screen and press 2nd MATH 4[Matrix] 2[det(] A ) ENTER. You should
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Keystrokes
2nd MATH 4 D 2 E, 1, 2 ) STO➧ E ENTER
2nd MATH 4 D 4 (-) 2, E, 1 , 3) STO➧ E
ENTER
2nd MATH 4 D 2 E, 2, 3) STO➧ E ENTER
2nd MATH 4 D 3 1 ÷ 2, E, 3) STO➧ E
ENTER
−
 1 2 3 
 
− 
1 3 0 . Since this consists of the first

 
−
2 5 5
 
Figure 5.82: Inverse of a