From: A. N. Emus on
An Elementary Proof of Fermat's 'Last Theorem'
by A. N. Emus


The equation x^n + y^n = z^n {1}
has no solution in positive integers x, y, z, n if
n > 2.

Proof:

By symmetry we can suppose x < y. Clearly, y < z.

Rewrite {1} as

x^m(x^2) + y^m(y^2) = z^m(z^2), {2}

where m >= 1 must be some integer.

Rewrite {2} as

x^m(x^2) + (x^m + a)y^2 = (x^m + b)z^2, {3}

where a and b must be some positive integers.
Clearly, a < b.

Rearrange {3} as

x^m(x^2 + y^2 - z^2) = bz^2 - ay^2. {4}


There are three choices:

[1] x^2 + y^2 - z^2 < 0.

[2] x^2 + y^2 - z^2 > 0.

[3] x^2 + y^2 - z^2 = 0.


Choices [1] and [2] are not possible, otherwise the
left side of {1} would be either less than or greater
than the right side. This leaves [3] as the only
choice. Then, from {4}, bz^2 - ay^2 = 0. This is not
possible considering a < b and y < z.

*******
From: master1729 on
> An Elementary Proof of Fermat's 'Last Theorem'
> by A. N. Emus
>
>
> The equation x^n + y^n = z^n
> {1}
> has no solution in positive integers x, y, z, n if
> n > 2.
>
> Proof:
>
> By symmetry we can suppose x < y. Clearly, y < z.
>
> Rewrite {1} as
>
> x^m(x^2) + y^m(y^2) = z^m(z^2),
> 2) = z^m(z^2), {2}
>
> where m >= 1 must be some integer.
>
> Rewrite {2} as
>
> x^m(x^2) + (x^m + a)y^2 = (x^m + b)z^2,
> + b)z^2, {3}
>
> where a and b must be some positive integers.
> Clearly, a < b.
>
> Rearrange {3} as
>
> x^m(x^2 + y^2 - z^2) = bz^2 - ay^2.
> z^2 - ay^2. {4}
>
>
> There are three choices:
>
> [1] x^2 + y^2 - z^2 < 0.
>
> [2] x^2 + y^2 - z^2 > 0.
>
> [3] x^2 + y^2 - z^2 = 0.
>
>
> Choices [1] and [2] are not possible, otherwise the
> left side of {1} would be either less than or
> greater
> than the right side. This leaves [3] as the only
> choice. Then, from {4}, bz^2 - ay^2 = 0. This is
> not
> possible considering a < b and y < z.
>
> *******

not bad , [1] and [3] are indeed impossible.

but you didnt prove [2] to be impossible.

x^2 + y^2 - z^2 > 0

x^3 + y^3 - z^3 < 0

e.g. x = 5 y = 6 z = 7.

tommy1729
From: Tim Little on
On 2010-07-14, A. N. Emus <lainiech(a)msn.com> wrote:
[ To prove: x^n + y^n = z^n {1} has no integer solutions for n > 2 ...]
> By symmetry we can suppose x < y. Clearly, y < z.
[...]
> x^m(x^2) + y^m(y^2) = z^m(z^2), {2}
[...]
> x^m(x^2) + (x^m + a)y^2 = (x^m + b)z^2, {3}
> where a and b must be some positive integers. Clearly, a < b.
[...]
> x^m(x^2 + y^2 - z^2) = bz^2 - ay^2. {4}
>
> There are three choices:
>
> [1] x^2 + y^2 - z^2 < 0.
> [2] x^2 + y^2 - z^2 > 0.
> [3] x^2 + y^2 - z^2 = 0.
>
> Choices [1] and [2] are not possible, otherwise the left side of {1}
> would be either less than or greater than the right side.

Why? Your reasoning is certainly incorrect for non-integer solutions
to {1}, and you have given no reason to suppose that it holds for
integers.


- Tim
From: Bobby Simione on
On Jul 14, 10:06 pm, master1729 <tommy1...(a)gmail.com> wrote:
> > An Elementary Proof of Fermat's 'Last Theorem'
> > by A. N. Emus
>
> > The equation          x^n + y^n = z^n
> >                {1}
> > has no solution in positive integers x, y, z, n if
> > n > 2.
>
> > Proof:
>
> > By symmetry we can suppose x < y.  Clearly, y < z.
>
> > Rewrite {1} as
>
> > x^m(x^2) + y^m(y^2) = z^m(z^2),
> > 2) = z^m(z^2),        {2}
>
> > where m >= 1 must be some integer.
>
> > Rewrite {2} as
>
> > x^m(x^2) + (x^m + a)y^2 = (x^m + b)z^2,
> > + b)z^2,     {3}
>
> > where a and b must be some positive integers.
> > Clearly, a < b.
>
> > Rearrange {3} as
>
> > x^m(x^2 + y^2 - z^2) = bz^2 - ay^2.
> > z^2 - ay^2.       {4}
>
> > There are three choices:
>
> > [1] x^2 + y^2 - z^2 < 0.
>
> > [2] x^2 + y^2 - z^2 > 0.
>
> > [3] x^2 + y^2 - z^2 = 0.
>
> > Choices [1] and [2] are not possible, otherwise the
> > left side of {1} would be either less than or
> > greater
> > than the right side.  This leaves [3] as the only
> > choice.  Then, from {4}, bz^2 - ay^2 = 0.  This is
> > not
> > possible considering a < b and y < z.
>
> >                     *******
>
> not bad , [1] and [3] are indeed impossible.
>
> but you didnt prove [2] to be impossible.
>
> x^2 + y^2 - z^2 > 0
>
> x^3 + y^3 - z^3 < 0
>
> e.g. x = 5 y = 6 z = 7.
>
> tommy1729- Hide quoted text -
>
> - Show quoted text -

Agreed, case [2] can be proved true if you consider that x < y, and
notice that you can use the triangle inequality to a suitable norm.
(l^n norm for the correct n ;) ).
-Robert
From: curious george on

"Tim Little" <tim(a)little-possums.net> wrote in message
news:slrni3t4js.jrj.tim(a)soprano.little-possums.net...
> On 2010-07-14, A. N. Emus <lainiech(a)msn.com> wrote:
> [ To prove: x^n + y^n = z^n {1} has no integer solutions for n > 2 ...]
>> By symmetry we can suppose x < y. Clearly, y < z.
> [...]
>> x^m(x^2) + y^m(y^2) = z^m(z^2), {2}
> [...]
>> x^m(x^2) + (x^m + a)y^2 = (x^m + b)z^2, {3}
>> where a and b must be some positive integers. Clearly, a < b.
> [...]
>> x^m(x^2 + y^2 - z^2) = bz^2 - ay^2. {4}
>>
>> There are three choices:
>>
>> [1] x^2 + y^2 - z^2 < 0.
>> [2] x^2 + y^2 - z^2 > 0.
>> [3] x^2 + y^2 - z^2 = 0.
>>
>> Choices [1] and [2] are not possible, otherwise the left side of {1}
>> would be either less than or greater than the right side.
>
> Why? Your reasoning is certainly incorrect for non-integer solutions
> to {1}, and you have given no reason to suppose that it holds for
> integers.
>
>
> - Tim
>

Tim, how about telling the rest of us why you think his "reasoning is
certainly incorrect". How incorrect is it? 51% or 99.99999%. an
unsubstantiated answer to an unsubstantiated claim ( according to you ).