# Matrices

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• Jan 25th 2013, 04:56 AM
Suddenli
Re: Matrices
Thank you very much for the info. I have been looking for this info for the last few days. Your efforts are appreciated.

Heart rhythm problems
• Jan 25th 2013, 05:08 AM
Deveno
Re: Matrices
Quote:

Originally Posted by tmoria
an interesting point from my earlier error though...

treating as ordinary algebra

\$\displaystyle AY^{-1}=B\$

\$\displaystyle Y^{-1}=\dfrac {B}{A}\$

since \$\displaystyle \dfrac{1}{A}=A^{-1}\$

we have \$\displaystyle Y^{-1}=A^{-1}B\$

which agrees with your matrix solution.

Is this true in all situations or just peculiar to this one ?

it's true of all situations where the concept of "multiplicative inverse" is well-defined. the horizontal bar refers to a particular kind of inverse, one defined by division (usually reserved for elements of a field, or a localization of a ring).
• Jan 25th 2013, 11:20 AM
tmoria
Re: Matrices
Thanks for clarifying that Deveno, I was never keen on matrices when I was at school a looonnnggg time ago.
• Jan 25th 2013, 02:33 PM
ILikeSerena
Re: Matrices
Quote:

Originally Posted by Deveno
this makes no sense, for vectors OR matrices, division is not defined.

I thought division was usually defined as multiplication with the inverse.
It works perfectly for matrices.
See e.g. Division (mathematics) - Wikipedia, the free encyclopedia
Furthermore, next to right division, we have left division (denoted \).
• Jul 30th 2013, 05:50 AM
Gmushroom
Re: Matrices
I Defines here matrices and basic matrix terms, illustrating these terms with worked solutions to typical homework exercises.