Concept Byte: Working with Matrices
For Use With Lesson 12-1
TECHNOLOGY
You can use a graphing calculator to work with matrices. First you need to know how to enter a matrix into the calculator.
Example 1
Enter matrix
A
=
[
−
3
4
7
−
5
0
−
2
]
eh equals . matrix with 3 rows and 2 columns , row1 column 1 , negative 3 , column 2 4 , row2 column 1 , 7 , column 2 negative 5 , row3 column 1 , 0 , column 2 negative 2 , end matrix into your graphing calculator.
Select the EDIT option of the
matrix
begin box , matrix , end box feature to edit matrix [A]. Specify a
3
×
2
3 times 2 matrix by pressing
3
enter
2
enter
.
begin box , 3 , end box , begin box , enter , end box , begin box , 2 , end box , begin box , enter , end box , . Enter the matrix elements one row at a time, pressing
enter
begin box , enter , end box after each element. Then use the
quit
begin box , quit , end box feature to return to the main screen.
Image Long Description
Example 2
Given
A
=
[
−
3
4
7
−
5
0
−
2
]
eh equals . matrix with 3 rows and 2 columns , row1 column 1 , negative 3 , column 2 4 , row2 column 1 , 7 , column 2 negative 5 , row3 column 1 , 0 , column 2 negative 2 , end matrix and
B
=
[
10
−
7
4
−
3
−
12
11
]
,
b equals . matrix with 3 rows and 2 columns , row1 column 1 , 10 , column 2 negative 7 , row2 column 1 , 4 , column 2 negative 3 , row3 column 1 , negative 12 , column 2 11 , end matrix . comma find A
+
B
and
A
−
B
.
eh minus b .
Enter both matrices into the calculator. Use the NAMES option of the
matrix
begin box , matrix , end box feature to select each matrix. Press
enter
begin box , enter , end box to see the sum. Repeat the corresponding steps to find the difference
A
−
B
.
eh minus b .
Image Long Description
Exercises
Find each sum or difference.
-
[
0
−
3
5
−
7
]
−
[
−
5
3
4
10
]
table with 1 row and 3 columns , row1 column 1 , . matrix with 2 rows and 2 columns , row1 column 1 , 0 , column 2 negative 3 , row2 column 1 , 5 , column 2 negative 7 , end matrix , column 2 minus , column 3 . matrix with 2 rows and 2 columns , row1 column 1 , negative 5 , column 2 3 , row2 column 1 , 4 , column 2 10 , end matrix , end table
-
[
3
5
−
7
0
−
2
0
]
−
[
−
1
6
2
−
9
4
0
]
table with 1 row and 3 columns , row1 column 1 , . matrix with 2 rows and 3 columns , row1 column 1 , 3 , column 2 5 , column 3 negative 7 , row2 column 1 , 0 , column 2 negative 2 , column 3 0 , end matrix , column 2 minus , column 3 . matrix with 2 rows and 3 columns , row1 column 1 , negative 1 , column 2 6 , column 3 2 , row2 column 1 , negative 9 , column 2 4 , column 3 0 , end matrix , end table
-
[
3
5
]
−
[
−
6
7
]
table with 1 row and 3 columns , row1 column 1 , , matrix with 2 rows and 1 column , row1 column 1 , 3 , row2 column 1 , 5 , end matrix , column 2 minus , column 3 . matrix with 2 rows and 1 column , row1 column 1 , negative 6 , row2 column 1 , 7 , end matrix , end table
-
[
3
5
−
8
]
+
[
−
6
4
1
]
left bracket 3 5 minus 8 right bracket plus left bracket negative 6 4 1 right bracket
-
[
17
8
0
3
−
5
2
]
−
[
4
6
5
2
−
2
9
]
table with 1 row and 3 columns , row1 column 1 , . matrix with 2 rows and 3 columns , row1 column 1 , 17 , column 2 8 , column 3 0 , row2 column 1 , 3 , column 2 negative 5 , column 3 2 , end matrix , column 2 minus , column 3 . matrix with 2 rows and 3 columns , row1 column 1 , 4 , column 2 6 , column 3 5 , row2 column 1 , 2 , column 2 negative 2 , column 3 9 , end matrix , end table
-
[
−
9
6
4
]
+
[
−
3
8
4
]
left bracket negative 9 6 4 right bracket plus left bracket negative 3 8 4 right bracket
