Error
There was an error loading the page.
This question asks learners to use row operations to find the inverse of a 3x3 matrix.
Metadata
Taxonomy: mathcentre
Taxonomy: Kind of activity
Taxonomy: Context
Contributors
History
Stephen Flood 7 years, 3 months ago
Created this.There is only one version of this question that you have access to.
There are 3 other versions that do you not have access to.
| Name | Type | Generated Value |
|---|
| a11 | integer |
2
|
||||
| a12 | integer |
2
|
||||
| a13 | integer |
0
|
||||
| k | integer |
3
|
||||
| a21 | integer |
6
|
||||
| a22 | integer |
7
|
||||
| a23 | integer |
5
|
||||
| k1 | integer |
4
|
||||
| a31 | integer |
8
|
||||
| a32 | integer |
12
|
||||
| a33 | integer |
21
|
||||
| k2 | integer |
-10
|
||||
| k3 | integer |
5
|
Generated value: integer
This variable doesn't seem to be used anywhere.
Gap-fill
Ask the student a question, and give any hints about how they should answer this part.
First set up the augmented matrix:
({a11}{a12}{a13}{1}{0}{0}{a21}{a22}{a23}{0}{1}{0}{a31}{a32}{a33}{0}{0}{1})
Use appropriate row operations to get zeroes below the diagonal in the first column:
({a11}{a12}{a13}{1}{0}{0}01????0?????) =
Taking this matrix apply the appropriate row operations to get zeroes above and below the diagonal in column 2 as shown below:
({a11}0?{1}??01????00????) =
Next take this matrix and apply the appropriate row operations to get zeroes above the diagonal in column 3 as shown below:
({a11}00???010???001???) =
By carrying out one final row operation input all the entries in A−1, correct to two decimal places.
A−1 =
Use this tab to check that this question works as expected.
| Part | Test | Passed? |
|---|---|---|
| Gap-fill | ||
| Hasn't run yet | ||
| Matrix entry | ||
| Hasn't run yet | ||
| Matrix entry | ||
| Hasn't run yet | ||
| Matrix entry | ||
| Hasn't run yet | ||
| Matrix entry | ||
| Hasn't run yet |
This question is used in the following exam: