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Question About the Eth Root of E

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Michael Ejercito

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Apr 9, 2009, 9:22:51 PM4/9/09
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If e is the base of the natural logarithm, then is the eth root of
e rational?


Michael

Tim Little

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Apr 9, 2009, 11:29:43 PM4/9/09
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On 2009-04-10, Michael Ejercito <meje...@hotmail.com> wrote:
> If e is the base of the natural logarithm, then is the eth root of e
> rational?

I don't know, and no simple arguments eitehr way have occurred to me.
I do know that it is not known whether some possibly "simpler"
expressions are rational, such as 2^e.


- Tim

A N Niel

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Apr 10, 2009, 7:49:07 AM4/10/09
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In article
<eb44ea05-e3b3-4ec2...@w40g2000yqd.googlegroups.com>,
Michael Ejercito <meje...@hotmail.com> wrote:


Of course it is irrational. Fortunately for me, you did not ask for a
proof!

Michael Ejercito

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Apr 10, 2009, 11:26:48 AM4/10/09
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On Apr 10, 4:49 am, A N Niel <ann...@nym.alias.net.invalid> wrote:
> In article
> <eb44ea05-e3b3-4ec2-94e3-90c4fe1f5...@w40g2000yqd.googlegroups.com>,

>
> Michael Ejercito<mejer...@hotmail.com> wrote:
> >    If e is the base of the natural logarithm, then is the eth root of
> > e rational?
>
> >  Michael
>
> Of course it is irrational.  Fortunately for me, you did not ask for a
> proof!
What is the proof?


Michael

pubkeybreaker

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Apr 10, 2009, 12:32:44 PM4/10/09
to

It would follow immediately from Shanuel's Conjecture.

If e^1/e is rational, then
e = 1/(log a - log b) for some integers a,b.

The LHS has transcendence degree 1, while the rhs has transcendence
degree 2
by Shanuel.

Otherwise:

I suspect that this is provable using the same technique
that Hermite used to prove e is transcendental. Treat
1/(log(x) - log(k)) as a infinite series for some fixed k
and show that its partial sums do not approximate e sufficiently
well for all k.

Michael Ejercito

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Apr 11, 2009, 12:48:19 PM4/11/09
to
On Apr 10, 9:32 am, pubkeybreaker <pubkeybrea...@aol.com> wrote:

> On Apr 10, 11:26 am,Michael Ejercito<mejer...@hotmail.com> wrote:
>
> > On Apr 10, 4:49 am, A N Niel <ann...@nym.alias.net.invalid> wrote:> In article
> > > <eb44ea05-e3b3-4ec2-94e3-90c4fe1f5...@w40g2000yqd.googlegroups.com>,
>
> > >Michael Ejercito<mejer...@hotmail.com> wrote:
> > > >    If e is the base of the natural logarithm, then is the eth root of
> > > > e rational?
>
> > > >  Michael
>
> > > Of course it is irrational.  Fortunately for me, you did not ask for a
> > > proof!
>
> >    What is the proof?
>
> It would follow immediately from Shanuel's Conjecture.
>
> If e^1/e is rational,  then
> e = 1/(log a  - log b)   for some integers a,b.
How do you derive that? I put in the equation e^(1/e)=a/b, raised
both sides to the e power to get e=a^e/b^e, and then taking the common
logarithm of both sides yields log (e)=e log(a) + e log (b)
(approximately 0.434294481).

>
> The LHS has transcendence degree 1, while the rhs has transcendence
> degree 2
> by Shanuel.
>
> Otherwise:
>
> I suspect that this is provable using the same technique
> that Hermite used to prove e is transcendental.   Treat
> 1/(log(x) - log(k))  as a infinite series for some fixed k
> and show that its partial sums do not approximate e sufficiently
> well for all k.
What is the proof for Shaunel's Conjecture?


Michael

G. A. Edgar

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Apr 11, 2009, 1:24:56 PM4/11/09
to
In article
<64389956-39e8-4ffa...@d38g2000prn.googlegroups.com>,
Michael Ejercito <meje...@hotmail.com> wrote:

> On Apr 10, 9:32 am, pubkeybreaker <pubkeybrea...@aol.com> wrote:
> > On Apr 10, 11:26 am,Michael Ejercito<mejer...@hotmail.com> wrote:
> >
> > > On Apr 10, 4:49 am, A N Niel <ann...@nym.alias.net.invalid> wrote:> In
> > > article
> > > > <eb44ea05-e3b3-4ec2-94e3-90c4fe1f5...@w40g2000yqd.googlegroups.com>,
> >
> > > >Michael Ejercito<mejer...@hotmail.com> wrote:
> > > > >    If e is the base of the natural logarithm, then is the eth root of
> > > > > e rational?
> >
> > > > >  Michael
> >
> > > > Of course it is irrational.  Fortunately for me, you did not ask for a
> > > > proof!
> >
> > >    What is the proof?
> >
> > It would follow immediately from Shanuel's Conjecture.
> >
> > If e^1/e is rational,  then
> > e = 1/(log a  - log b)   for some integers a,b.
> How do you derive that? I put in the equation e^(1/e)=a/b, raised
> both sides to the e power to get e=a^e/b^e, and then taking the common
> logarithm of both sides

"log" is used for the natural logarithm by mathematicians

> yields log (e)=e log(a) + e log (b)
> (approximately 0.434294481).

log(e) = 1, solve for e

> >
> > The LHS has transcendence degree 1, while the rhs has transcendence
> > degree 2 by Shanuel.
> >
> > Otherwise:
> >
> > I suspect that this is provable using the same technique
> > that Hermite used to prove e is transcendental.   Treat
> > 1/(log(x) - log(k))  as a infinite series for some fixed k
> > and show that its partial sums do not approximate e sufficiently
> > well for all k.
> What is the proof for Shaunel's Conjecture?

Unknown. That is why it is called a conjecture. But the "log" in it
is the natural logarithm.

>
>
> Michael

--
G. A. Edgar http://www.math.ohio-state.edu/~edgar/

Toni...@yahoo.com

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Apr 11, 2009, 1:35:34 PM4/11/09
to
On Apr 11, 7:48 pm, Michael Ejercito <mejer...@hotmail.com> wrote:
> On Apr 10, 9:32 am, pubkeybreaker <pubkeybrea...@aol.com> wrote:
>
>
>
> > On Apr 10, 11:26 am,Michael Ejercito<mejer...@hotmail.com> wrote:
>
> > > On Apr 10, 4:49 am, A N Niel <ann...@nym.alias.net.invalid> wrote:> In article
> > > > <eb44ea05-e3b3-4ec2-94e3-90c4fe1f5...@w40g2000yqd.googlegroups.com>,
>
> > > >Michael Ejercito<mejer...@hotmail.com> wrote:
> > > > >    If e is the base of the natural logarithm, then is the eth root of
> > > > > e rational?
>
> > > > >  Michael
>
> > > > Of course it is irrational.  Fortunately for me, you did not ask for a
> > > > proof!
>
> > >    What is the proof?
>
> > It would follow immediately from Shanuel's Conjecture.
>
> > If e^1/e is rational,  then
> > e = 1/(log a  - log b)   for some integers a,b.
>
>    How do you derive that? I put in the equation e^(1/e)=a/b, raised
> both sides to the e power to get e=a^e/b^e, and then taking the common
> logarithm of both sides yields log (e)=e log(a) + e log (b)
> (approximately 0.434294481).
>
************************************************************

You got it wrong: log(A/B) = log A - log B, so:

e = a^e/b^e ==> 1 = log e = e[log a - log b], and from here the
expression for e.

Regards
Tonio


> > The LHS has transcendence degree 1, while the rhs has transcendence
> > degree 2
> > by Shanuel.
>
> > Otherwise:
>
> > I suspect that this is provable using the same technique
> > that Hermite used to prove e is transcendental.   Treat
> > 1/(log(x) - log(k))  as a infinite series for some fixed k
> > and show that its partial sums do not approximate e sufficiently
> > well for all k.
>
>    What is the proof for Shaunel's Conjecture?
>

>  Michael- Hide quoted text -
>
> - Show quoted text -

Noone

unread,
Apr 11, 2009, 1:48:12 PM4/11/09
to
On Sat, 11 Apr 2009 09:48:19 -0700 (PDT), Michael Ejercito
<meje...@hotmail.com> wrote:

>On Apr 10, 9:32 am, pubkeybreaker <pubkeybrea...@aol.com> wrote:
>> On Apr 10, 11:26 am,Michael Ejercito<mejer...@hotmail.com> wrote:
>>
>> > On Apr 10, 4:49 am, A N Niel <ann...@nym.alias.net.invalid> wrote:> In article
>> > > <eb44ea05-e3b3-4ec2-94e3-90c4fe1f5...@w40g2000yqd.googlegroups.com>,
>>
>> > >Michael Ejercito<mejer...@hotmail.com> wrote:
>> > > >    If e is the base of the natural logarithm, then is the eth root of
>> > > > e rational?
>>
>> > > >  Michael
>>
>> > > Of course it is irrational.  Fortunately for me, you did not ask for a
>> > > proof!
>>
>> >    What is the proof?
>>
>> It would follow immediately from Shanuel's Conjecture.
>>
>> If e^1/e is rational,  then
>> e = 1/(log a  - log b)   for some integers a,b.
> How do you derive that? I put in the equation e^(1/e)=a/b, raised
>both sides to the e power to get e=a^e/b^e, and then taking the common
>logarithm of both sides yields log (e)=e log(a) + e log (b)
>(approximately 0.434294481).

Why raise things to a power? Simply take the natural log of both
sides and realize that log(e) = 1.

e^(1/e) = a/b

1/e log(e) = log(a/b)

Solve for e.

>>
>> The LHS has transcendence degree 1, while the rhs has transcendence
>> degree 2
>> by Shanuel.
>>
>> Otherwise:
>>
>> I suspect that this is provable using the same technique
>> that Hermite used to prove e is transcendental.   Treat
>> 1/(log(x) - log(k))  as a infinite series for some fixed k
>> and show that its partial sums do not approximate e sufficiently
>> well for all k.
> What is the proof for Shaunel's Conjecture?

A proof it not known, which is why it remains a conjecture.

>
>
> Michael

Michael Ejercito

unread,
Apr 11, 2009, 7:14:54 PM4/11/09
to
On Apr 11, 10:48 am, Noone <no...@domain.invalid> wrote:
> On Sat, 11 Apr 2009 09:48:19 -0700 (PDT), Michael Ejercito
>
>
>
> <mejer...@hotmail.com> wrote:
> >On Apr 10, 9:32 am, pubkeybreaker <pubkeybrea...@aol.com> wrote:
> >> On Apr 10, 11:26 am,Michael Ejercito<mejer...@hotmail.com> wrote:
>
> >> > On Apr 10, 4:49 am, A N Niel <ann...@nym.alias.net.invalid> wrote:> In article
> >> > > <eb44ea05-e3b3-4ec2-94e3-90c4fe1f5...@w40g2000yqd.googlegroups.com>,
>
> >> > >Michael Ejercito<mejer...@hotmail.com> wrote:
> >> > > >    If e is the base of the natural logarithm, then is the eth root of
> >> > > > e rational?
>
> >> > > >  Michael
>
> >> > > Of course it is irrational.  Fortunately for me, you did not ask for a
> >> > > proof!
>
> >> >    What is the proof?
>
> >> It would follow immediately from Shanuel's Conjecture.
>
> >> If e^1/e is rational,  then
> >> e = 1/(log a  - log b)   for some integers a,b.
> >   How do you derive that? I put in the equation e^(1/e)=a/b, raised
> >both sides to the e power to get e=a^e/b^e, and then taking the common
> >logarithm of both sides yields log (e)=e log(a) + e log (b)
> >(approximately 0.434294481).
>
> Why raise things to a power?  Simply take the natural log of both
> sides and realize that log(e) = 1.
>
It does?

when I enter 2.718281828 into my computer's calculator and click
the log function key, I get 0.434294481.


Michael

A N Niel

unread,
Apr 11, 2009, 8:22:00 PM4/11/09
to
In article
<d6337140-0c4d-4b2b...@d7g2000prl.googlegroups.com>,
Michael Ejercito <meje...@hotmail.com> wrote:

> when I enter 2.718281828 into my computer's calculator and click
> the log function key, I get 0.434294481.

Your calculator seems to use the common log. Mathematicians use the
natural log. See if your calculator has a "ln" key for the natural
log.

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