Exploring A Matrix - Texas Instruments TI-89 Manual Book

Exploring a Matrix

Exploring a 3x3
Matrix
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388 Chapter 23: Activities
This activity shows you how to perform several matrix
operations.
Perform these steps to generate a random matrix, augment and find
the identity matrix, and then solve to find an invalid value of the
inverse.
1. On the Home screen, use
RandSeed to set the random
number generator seed to the
factory default, and then use
to create a random
randMat()
3x3 matrix and store it in
2. Replace the element of the
[2,3]
matrix with the variable
then use the
augment()
function, to augment the 3x3
identity to and store the
a
result in .
b
3. Use to "row reduce"
rref()
matrix :
b
The result will have the
identity matrix in the first
three columns and
last three columns.
4. Solve for the value of
will cause the inverse of the
matrix to be invalid.
Enter: solve(getDenom(
2 ± [1,4] )=0,x)
Result: x=ë 70/17
.
a
, and
x
in the
a^ë 1
that
x