Similarity of Diagonalizable Matrices

  • Thread starter Thread starter flybynight
  • Start date Start date
  • Tags Tags
    Matrices
flybynight
Messages
14
Reaction score
0

Homework Statement


A = {{2,1,0}{0,-2,1}{0,0,1}} and B = {{3,2,-5}{1,2,-1}{2,2,-4}}
Show that A and B are similar by showing that they are similar to the same diagonal matrix. Then find an invertible matrix P such that P-1AP=B

Homework Equations


P-1AP=B, or AP=PB

The Attempt at a Solution


I found the eigenvalues of both matrices to be 2, -2 and 1. I have created the matrix D={{2,0,0}{0,-2,0}{0,0,1}}. But I don't know where to go from there. Any help would be greatly appreciated.
 
Physics news on Phys.org
flybynight said:

Homework Statement


A = {{2,1,0}{0,-2,1}{0,0,1}} and B = {{3,2,-5}{1,2,-1}{2,2,-4}}
Show that A and B are similar by showing that they are similar to the same diagonal matrix. Then find an invertible matrix P such that P-1AP=B

Homework Equations


P-1AP=B, or AP=PB

The Attempt at a Solution


I found the eigenvalues of both matrices to be 2, -2 and 1. I have created the matrix D={{2,0,0}{0,-2,0}{0,0,1}}. But I don't know where to go from there. Any help would be greatly appreciated.

Do you know how to diagonalize A itself, in other words how to build P using the eigenvectors of A to get P-1AP=D?
 
Yes, I know how to diagonalize the matrices.
 
Do you know how similarity matrices work? What linear transformation do they represent?
 
flybynight said:
Yes, I know how to diagonalize the matrices.

Well, if you can make P-1AP = D and Q-1BQ = D what is the relationship between A and B?
 
Back
Top