Re: Re: Problem with limiits
- To: mathgroup at smc.vnet.net
- Subject: [mg65855] Re: [mg65845] Re: Problem with limiits
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Wed, 19 Apr 2006 04:54:03 -0400 (EDT)
- References: <200604160544.BAA07913@smc.vnet.net> <e1vdsq$967$1@smc.vnet.net> <200604181056.GAA14316@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
On 18 Apr 2006, at 19:56, Roger Bagula wrote:
> Andrzej Kozlowski wrote:
>
>>
>> For any sequence of real numbers a1,a2, a3 .... converging to a real
>> number L, any infinite subsequence of it will converge to the same
>> limit L. This is a very basic fact and is in fact true in any
>> complete metric space (a subsequence of a convergent sequence is a
>> Cauchy sequence, and therefore, in a complete metric space, is itself
>> convergent.)
>>
>> Given the above, you only need the fact that there are infinitely
>> many primes (proved by Euclid and before him by Eudoxus).
>>
>> Andrzej Kozlowski
>>
> What you are saying is that if I have a composite number c[m]
> them the Limit:
>
> Limit[(1+1/c[m])^c[m],m->Infinity]=E
>
> as well.
> What About:
> Limit[(1-1/m)^m,m->Infinity] =1/E
>
> Your reasoning gives:
> Limit[(1-1/c[n])^c[n],n->Infinity]*Limit[(1+1/Prime[n])^Prime[n],N-
> >Infinity]=1
> and
> Limit[(1-1/m)^m,m->Infinity]*Limit[(1+1/m)^m,m->Infinity]=1
> This does give:
> Limit[(1 - 1/m^2)^m, m -> Infinity]=1
>
> Thanks for your help.
>
No, I am saying that you have to have a *sub-sequence*.
(1+1/Prime[n])^Prime[n] for n from 1 to Infinity is a sub-sequence
of (1 + 1/m)^m from 1 to Infinity. If you can't see this general fact
just look at
Table[(1 + 1/Prime[n])^Prime[n], {n, 1, 3}]
{9/4, 64/27, 7776/3125}
and
Table[(1 + 1/m)^m, {m, 1, 5}]
{2, 9/4, 64/27, 625/256, 7776/3125}
and it should become clear.
On the other hand:
(1-1/m)^m for m from 1 to Infinity is not a sub-sequence of (1 + 1/n)
^n from 1 to Infinity.
Just look at the first few terms:
Table[(1 - 1/m)^m, {m, 1, 5}]
{0, 1/4, 8/27, 81/256, 1024/3125}
Do I need to say more?
Andrzej Kozlowski
- References:
- Problem with limiits
- From: Roger Bagula <rlbagulatftn@yahoo.com>
- Re: Problem with limiits
- From: Roger Bagula <rlbagulatftn@yahoo.com>
- Problem with limiits