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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,602

I have three new pages for you all to look at (and comment on):

Inverse of a Matrix using Elementary Row Operations Gauss-Jordan

Inverse of a Matrix using Minors Cofactors and Adjugate

Enjoy! (And find any faults, too, please)

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,248

Hi MIF;

On the first one, Inverse of a matrix.

It is all correct, appealing to the eye and well thought out. Why did you choose the form of row vectors rather than the more common form of column vectors?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,602

I think perhaps I should, as it is the more common form. But it leads people to think that the heights (number of rows) are "naturally" matched ... if you see what I mean. When you approach it the other way then you need to think more about sizes of rows and columns.

Please let me know your thoughts.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,248

That is okay with me. Then keep it the way that is more didactic.

Second page is excellent.

Third page also fine as far as I can tell. I never used that method before. Actually I have never computed an adjoint or cofactor of a matrix.

Thanks for providing the pages.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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