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Author Message
William Hughes
Posted: Wed Dec 17, 2003 8:08 pm
Guest
jstevh@msn.com (James Harris) wrote in message news:<3c65f87.0312170701.d6b8762@posting.google.com>...
Quote:
wpihughes@hotmail.com (William Hughes) wrote in message news:<4d5e4663.0312150510.86bcfd1@posting.google.com>...
jstevh@msn.com (James Harris) wrote in message news:<3c65f87.0312141928.49c9b250@posting.google.com>...
Given, where x is in the ring of algebraic integers, I've shown the
factorization

(5 a_1(x) + 7)(5 a_2(x) + 7)(5 b_3(x) + 22) =

49(300125 x^3 - 18375 x^2 - 360 x + 22)

where b_3(x) = a_3(x) - 3 and the a's are roots of

a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)

so when x=0, a_1(0) = a_2(0) = b_3(0) = 0.

I'm curious about the mental processes that allow *some* of you to
claim that 49 divides off as a *variable* dependent on x, so I'm
giving another opportunity for you to speak your minds.

To my knowledge, in the history of mathematics, no one has ever
presented such a proposition, so it is a unique one, and I must say
that I'm intrigued.

Speak your minds.


James Harris

Why does this not count as presenting "such a proposition"?

Let g1(x)=4-sqrt(1+3x) and g2(x)=4+sqrt(1+3x).

then
g1(x)*g2(x) = 3(5-x)

I noted there's a *sign* ambiguity in the sqrt() operator, which
sparked a lot of debate.

One thing I found interesting is that posters ignored that if you
divide both sides by 3, with the convention that you're taking the
positive of the sqrt() operator for *integer* results, you have

1 + (1-sqrt(1+3x))/3

as a factor, which is an integer (remember x is an integer and
remember 1+3x is a square).

but neither g1 nor g2 is divisible by 3 for all x.

-"William Hughes"

Prove it.

Consider x =2:

g1(2)/3 = (4-sqrt(7))/3 is a root of the primitive, irreducible, non-monic
polynomial P(x)=3x^2 - 8x + 3. Thus g1(2)/3 is not an algebraic integer
and g1(2) is not divisible by 3.

Now James has made the bizzare claim that sqrt(x) and hence g1(x) must
be considered multi-valued, and furthmore if either value of g1(x) is divisible
by 3 then g1(x) is divisible by 3. So let's try the other square root of 7.

g1(2)/ = (4+sqrt(7))/3 is a root of the primitive, irreducible, non-monic
polynomial P(x)=3x^2 - 8x + 3. Thus g1(2)/3 is not an algebraic integer
and g1(2) is not divisible by 3.

So, even if we accept the ambiguity argument, g1(2) is not divisible by 3.

Similarly, g2(2) is not divisible by 3.

Thus neither g1 nor g2 is divisible by 3 for all x.

-William Hughes
William Hughes
Posted: Wed Dec 17, 2003 8:40 pm
Guest
jstevh@msn.com (James Harris) wrote in message news:<3c65f87.0312170701.d6b8762@posting.google.com>...
Quote:
wpihughes@hotmail.com (William Hughes) wrote in message news:<4d5e4663.0312150510.86bcfd1@posting.google.com>...
jstevh@msn.com (James Harris) wrote in message news:<3c65f87.0312141928.49c9b250@posting.google.com>...
Given, where x is in the ring of algebraic integers, I've shown the
factorization

(5 a_1(x) + 7)(5 a_2(x) + 7)(5 b_3(x) + 22) =

49(300125 x^3 - 18375 x^2 - 360 x + 22)

where b_3(x) = a_3(x) - 3 and the a's are roots of

a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)

so when x=0, a_1(0) = a_2(0) = b_3(0) = 0.

I'm curious about the mental processes that allow *some* of you to
claim that 49 divides off as a *variable* dependent on x, so I'm
giving another opportunity for you to speak your minds.

To my knowledge, in the history of mathematics, no one has ever
presented such a proposition, so it is a unique one, and I must say
that I'm intrigued.

Speak your minds.


James Harris

Why does this not count as presenting "such a proposition"?

Let g1(x)=4-sqrt(1+3x) and g2(x)=4+sqrt(1+3x).

then
g1(x)*g2(x) = 3(5-x)

I noted there's a *sign* ambiguity in the sqrt() operator, which
sparked a lot of debate.

One thing I found interesting is that posters ignored that if you
divide both sides by 3, with the convention that you're taking the
positive of the sqrt() operator for *integer* results, you have

1 + (1-sqrt(1+3x))/3

as a factor, which is an integer (remember x is an integer and
remember 1+3x is a square).

but neither g1 nor g2 is divisible by 3 for all x.

-"William Hughes"

Prove it. Readers should note that this poster presented a *later*
post claiming a result that covers integer results of the square root
operator but made a rather simple mistake. In my reply to that post I
noted the sign ambiguity in the square root operator.

However sqrt(x), where x is a square can be taken to be the positive
result since you can *give* the result, but the ambiguity remains if
you see sqrt(x) without a given value.

That is, for instance, sqrt(4) is 2 *or* -2, but by convention, it's
*usually* taken as 2, though if you do enough analysis you will run
into situations where you need the negative!!!


Well, if you dislike the function sqrt(x) so much, note this
alternate presentation [1]

Let g1(x) and g2(x) be the two roots of the quadratic

g^2 - 8g + 3(5-x)

For x=0, the roots are 3 and 5. Choose g1 and g2 such that
g1(0)=3 and g2(0) = 5

We have (the product of the roots is the constant term)

g1(x) g2(x) = 3(5-x)


Clearly g1(x)/3 and g2(x)/3 are both roots of

3g^2 - 8g + (5-x)

but for x=2 this is primitive, irreducible and non-monic. Hence
neither g1(2) nor g2(2) is divisible by 3.

-William Hughes

[1] My thanks to Rick Decker whose post I adapted
Gib Bogle
Posted: Sat Dec 20, 2003 2:20 pm
Guest
Me wrote:
Quote:
James Harris <jstevh@msn.com> wrote:

: Given, where x is in the ring of algebraic integers, I've shown the
: factorization

: (5 a_1(x) + 7)(5 a_2(x) + 7)(5 b_3(x) + 22) =
: 49(300125 x^3 - 18375 x^2 - 360 x + 22)
: where b_3(x) = a_3(x) - 3 and the a's are roots of
: a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)
: so when x=0, a_1(0) = a_2(0) = b_3(0) = 0.
: Now you can divide both sides by 49.

: Some posters have claimed that when you divide by 49, what results
: varies depending on what value x has.
: Do you understand?

I don't understand what you mean by the phrase "what results".

Please consider my question in the following step-by-step:

1) You get your factorization. I agree.
2) 49 divides right-hand side. I agree.
3) 49 divides left-hand side. I agree.
4) So when x=0 we get

(7)(7)(22) = 49(22) I agree.

5) But when x!=0 it's not immediately clear what results from this
equation. Simply because 7 divides the first two terms when x=0 does not
imply anything about when x!=0. Are you suggesting that 7 divides the
first two terms when x!=0? If so, could you please explain why?

: I'm curious to know if you will admit understanding now, or if you
: will continue to ask questions, so I ask again:
: Do you understand?

I will certainly admit understanding after you clear up my question.

JSH does not answer questions.

Gib
 
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