Re: Can someone explain this proof, please?



victor_meldrew_666@xxxxxxxxxxx wrote:

Timothy Murphy wrote:

I take it that your proof shows that if the solution is written
f(x) g(x) = C(x),
then we get the same solution on replacing x by 1/x
ie (x^n f(1/x)) (x^m g(1/x)) = x^{m+n} C(1/x) = C(x).

An easy way to see that f and g are reciprocal polynomials
is to note that each zero z of f is a root of unity
and so has modulus 1. As f has real coefficients the
conjugate of z which is z^{-1} is also a root. Hence
f is reciprocal.

So the second part of your Hypothesis H(j) -
that a_i = a_{n-i} and b_i = b_{m-i}
could have been proved first, as a lemma.
The inductive hypothesis would then simply have been
that a_i,b_i are 0 or 1, which is a very natural hypothesis.

I'm coming round to the view that the problem might have been
easier than I thought, though hardly "trivial".

--
Timothy Murphy
e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland
.



Relevant Pages

  • Re: Those pesky Apache permissions (was Re: (kein Betreff))
    ... index2.html),but replacing it with a new version of the file works ... A WinSCP weirdness? ... ,only the root was the owner of that folder and root was the group owner.... ... Maybe the Apache website ...
    (RedHat)
  • Re: Newbie problems with X11, Xf86
    ... try this (as root): ... this line in if you installed iceWM: ... or this one if you installed KDE (again replacing any other lines): ...
    (freebsd-questions)
  • Re: 7b5, or 7#11?
    ... above the root! ... I think the philosphy is that: ... would have been replacing. ... So sus 2 and "add 2" would of course mean the same thing. ...
    (rec.music.theory)
  • Re: Can someone explain this proof, please?
    ... Timothy Murphy wrote: ... An easy way to see that f and g are reciprocal polynomials ... is to note that each zero z of f is a root of unity ... Victor Meldrew ...
    (sci.math)
  • Re: restart end user workstations from remote
    ... Don't worry about it. ... Try replacing this line: ... (assuming that your shutdown folder is at the root of C) ...
    (microsoft.public.windows.server.active_directory)