On Oct 30, 2:30*pm, James Kuyper <(EMail Removed)> wrote:
> On 10/30/2012 01:26 PM, tom st denis wrote:
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> > On Oct 30, 12:57 pm, James Kuyper <(EMail Removed)> wrote:
> >> On 10/30/2012 12:38 PM, tom st denis wrote:
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> >>> On Oct 30, 12:13 pm, "BartC" <(EMail Removed)> wrote:
> >>>> "tom st denis" <(EMail Removed)> wrote in messagenews:(EMail Removed)...
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> >>>>> This is the equivalent of a math major asking us to help
> >>>>> them solve the matrix
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> >>>>> [ 2 1 ]
> >>>>> [ 1 1 ]
>
> >>>> What's the answer?
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> >>> R1R2 and then R2R1.
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> >> You haven't defined what R1 and R2 refer to, nor what those expressions
> >> mean.
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> > Row 1 and Row 2 ... are you really this dense?
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> >>> So x = 1 and y = 1 in this linear system.
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> >> Nor have you defined what x and y refer to.
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> > [2x 1y][3]
> > [1x 1y][2]
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> > Whatever, you're missing the point.
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> No  I understand precisely the point you were trying to make. I'm
> pointing out that you expressed it badly.
>
> > ... *Usually if I say "produce a
> > solution for this matrix" it means the program [or steps] required to
> > reduce it to REF.
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> Well, no, it doesn't  that's my point. It doesn't actually mean
> anything. A matrix doesn't have a solution.
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> An equation containing a matrix might (or might not) have a solution. If
> you have A*x=b, and A is a scalar, such as 5, you can say "solve for x
> in terms of b, and that's meaningful (unless A==0). You can also say
> "solve A", but that's not meaningful. If A is a matrix, like the one you
> gave above, and x and b are column vectors, you can also solve for x in
> terms of b (unless det(A)==0), but it's meaningless to ask someone to
> say "solve A", for exactly the same reason that it's meaningless to ask
> them to "solve A" when A == 5.
> You can ask them to invert A; if A is 5, that's just 1/5. If A is a
> matrix, that's more complicated; but that's not the same as asking them
> to "solve A".
If you're going to ignore what I write why did you reply?
I gave a perfectly good example of using that terminology [static
matrices] which you ignored to drone on about some offtopic math
related quibble.
Tom
