# Math Help - Matrices

1. ## 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

2. ## Re: Matrices

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

treating as ordinary algebra

$AY^{-1}=B$

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

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

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

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).

3. ## Re: Matrices

Thanks for clarifying that Deveno, I was never keen on matrices when I was at school a looonnnggg time ago.

4. ## Re: Matrices

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 \).

5. ## Re: Matrices

I Defines here matrices and basic matrix terms, illustrating these terms with worked solutions to typical homework exercises.