Linear algebra question

  • Thread starter LaraCroft
  • Start date
  • #1
14
0
Linear algebra question....

Hello again!

Ok...so if I let A =

[0 1 0 ]
[1 1 -2]
[2 3 -3]

How would I find A^-1? Is that the notation for inverse?

Also, could I express A^-1 as a product of at most five elementary matrices? What does this mean exactly?

Thanks!!:smile:
 

Answers and Replies

  • #2
lurflurf
Homework Helper
2,440
138


Elementary matrices are the representation of elementary operations. So see if you can get from the identity to A with five or fewer operations. Hint may help to instead see if you can go from A to I in five steps.

Elementary operations are
-interchange two rows
-multiply a row by a nonzero value
-add a multiple of a row to another
 
  • #3
HallsofIvy
Science Advisor
Homework Helper
41,847
964


Use row reduction to reduce A to the identity matrix. The elementary matrices corresponding to those row operations will multiply to give A-1.
 

Related Threads on Linear algebra question

  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
15
Views
4K
  • Last Post
Replies
2
Views
2K
Replies
14
Views
10K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
7
Views
2K
Top