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From: "Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Cofactor Matrix
Date: Thu, 6 Dec 2007 03:40:47 +0000 (UTC)
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shapper <mdmoura@gmail.com> wrote in message 
<5ab56294-93b4-4dbf-98e0-
e7aad594db5f@d21g2000prf.googlegroups.com>...
> Hello,
> 
> I am having a problem with the Cofactor matrix:
> http://en.wikipedia.org/wiki/Minor_%28linear_algebra%29
> 
> My problem is that I have the cofactor matrix and I need to find the
> original matrix. How can I do this?
> 
> My cofactor matrix is:
> 
> Cofactor of A = [-1 1 2; -2 1 4; 2 -1 -3]
> Det(A) = |A| = 1
> 
> How can I calculate the original matrix A?
> 
> Thanks,
> Miguel
--------
C =  [-1 1 2; -2 1 4; 2 -1 -3];
A = det(A)*eye(3)/C.'
   = [1 2 0;1 -1 1;2 0 1]

Roger Stafford