Re: Existence of function
- From: The World Wide Wade <aderamey.addw@xxxxxxxxxxx>
- Date: Fri, 16 Nov 2007 11:44:25 -0800
In article
<aderamey.addw-E6A981.11202115112007@xxxxxxxxxxxxxxxxxxxxxx>,
The World Wide Wade <aderamey.addw@xxxxxxxxxxx> wrote:
In article <1195130134.355299@athprx04>,
"I.N. Galidakis" <morpheus@xxxxxxxxxxxx> wrote:
This probably belongs to mathematical/philosophical existentialism, but
here
goes:
1) Person A claims that a certain real analytic function f having certain
properties exists.
2) Person B claims that f does not exist.
3) Person A then displays a sequence of series f_n(x)=sum(a_k*x^k,k=0..n),
(with
a_n calculated numerically) which appear to approximate the function f to
any
degree desired, but A cannot prove convergence of the f_n.
Has A proved the "existence" of f?
4) To make the case more interesting, assume that the convergence of the
series
f_n cannot be proved by algebraic means.
Does f exist?
Many thanks for any ideas,
Well suppose further A can prove convergence of the f_n. Suppose the
claim is that there exists a real analytic f on (-1,1) such that
f(1/k) = e^(-k), k = 2, 3, ... and A produces f_n's as above that
converge uniformly on (-1,1) to a function f such that f(1/k) = e^(-k)
for all k. Should B be convinced?
Never mind, I read the problem carelessly, not realizing the form of
the f_n's.
.
- References:
- Existence of function
- From: I.N. Galidakis
- Re: Existence of function
- From: The World Wide Wade
- Existence of function
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