Pythagorean Triples

Scatterplot of first pythagorean triples inside 4500
I had the pleasure of filling in for a colleague in her Discrete Structure class, which is basically our introduction to proof class. Currently they are covering some introductory concepts from Number Theory. One of my favorite results had been covered in the class just before I needed to fill in: The Euclidean Algorithm. Anyways, toward the end of class we introduced the concept of Pythagorean Triples.
Def: An ordered triple,
of positive integers such that
is called a pythagorean triple.
EX: (3, 4, 5)
EX: (6, 8, 10)
EX: (9, 12, 15)
EX: (5, 12, 13)
Notice that the first three examples are of the same "type." That is, the second and the third are multiples of the first. In fact, we could state the following theorem.
Thm: If
is a Pythagorean triple then for any positive integer
,
is also a Pythagorean triple.
Now, the last of my examples is fundamentally different from the other three. In fact, we could create a new definition.
Def: If the greatest common divisor of the pythagorean triple
is
, then it is called a primitive pythagorean triple. (In other words, if they have no common factors it is a primitive pythagorean triple)
I left the class with an question and recommended that if they were interested they should do a little research to find the answer.
Question: How many primitive pythagorean triples are there? That is, are there infinitely many or only some finite number of them?
Here are some interesting facts from Wikipedia about Pythagorean triples:
- Exactly one of a, b is odd, c is odd.
- Exactly one of a, b is divisible by 3
- Exactly one of a, b is divisible by 4
- Exactly one of a, b, c is divisible by 5
- Exactly one of a, b, (a+b), (a?b) is divisible by 7
- At most one of a, b is a square
- The hypotenuse, c, is an odd number
- Every integer greater than 2 is part of a Pythagorean triple
- The area (A=ab/2) is not an integer
- For any Pythagorean triple, the product of the two nonhypotenuse legs is always divisible by 12, and the product of all three sides is divisible by 60.
- There exist infinitely many primitive Pythagorean triples whose hypotenuses are squares of natural numbers.
- There exist infinitely many primitive Pythagorean triples of which one of the arms is the square of a natural number.
- For each natural number n, there exist n Pythagorean triples with different hypotenuses and the same area.
- For each natural number n, there exist at least n different Pythagorean triples with the same arm a, where a is some natural number
- For each natural number n, there exist at least n different triangles with the same hypotenuse.
- In every Pythagorean triple, the radius of the in-circle and the radii of the three ex-circles are natural numbers.
- There is no Pythagorean triple of which the hypotenuse and one arm are the arms of another Pythagorean triple.
July 24th, 2008 - 20:03
Do you happen to know if there are two Pythagorean triples with the same hypotenuse in which an arm in one is double an arm in the other: ie a,b,c is a triple and 2a,d,c is also a triple?
March 25th, 2009 - 10:40
There are a couple of problems above.
#1) A=ab/2 WOULD be an integer.
#2) If the greatest common factor of a set of numbers is 1, then it does have a GCF. You cannot say “(In other words, if they have no common factors it is a primitive pythagorean triple”
April 5th, 2009 - 13:41
Also, there are infinitely many primitive Pythagorean triples with a leg difference of 2N^2 – M^2, where N is any natural number and M is any odd number less than N, gcd(N,M)=1 and M is odd. In fact, I could list them for you!
See my paper on “Ordering the Primitive Pythagorean Triples by Leg Difference and Size Using Generalized Pell Sequences” in the Rational Argumentator: rationalargumentator.com/issue183/index183.html
April 11th, 2009 - 11:32
In response to Chris (above): No, I don’t believe such a pair of triples exists, but I don’t have a proof for you. I have an idea for one, though.
If {a, b, c} and {2a, d, c} were two triples, then by number theoretic arguments involving parity and the fact that squares are 0 or 1 mod 4, we could conclude, I think, that a must be even. Since I got a contradiction (that a is both even and odd) by assuming a to be odd.
Assuming a is even, I think we can also then assume these triples to be PPTs and eventually that c – a, c + a, c – 2a, and c + 2a are all perfect squares. And if x = c – 2a, then we can get that x, x + a, x + 3a, and x + 4a are all perfect squares. I’m pretty sure it can be proven without too much trouble that the squares simply can’t be spread out so linearly like that, no matter how you choose them.
Sorry. Best I can do for now.
April 12th, 2009 - 12:50
If we can assume that a is even, then there exist u and v, gcd(u,v)=1 such that {a, b, c} = {2uv, v^2-u^2, v^2 + u^2} and 2a = 4uv. So, we would be getting that c – 2a and c + 2a are squares, i.e. v^2 + u^2 – 4uv and v^2 + u^2 + 4uv are squares, but they aren’t even factorable using rationals!
Unless I’m mistaken somewhere, that’s the ballgame. No such triples exist where you get double a leg and the same hypotenuse.
April 14th, 2009 - 15:51
Yes, I am mistaken. That’s not sufficient, or at least I can’t prove that it is. But I’m so close to certain about squares not spreading linearly. And if v^2 + u^2 + 4uv is a square, then 2uv must equal 2u + 2v + 1, or 4u + 4v + 4, or 6u + 6v + 9, or 8u + 8v + 16, . . . Eliminating the odd numbers, factoring minorly and dividing by 2, we get that uv = 2(u + v + 1), or 4(u + v + 2), or 6(u + v + 3), , , , uv = 2n(u + v + n) for some natural number n. We can assume gcd(u,v)= 1 and that they are of opposite parity. Something’s gotta give, but I don’t know what.
April 14th, 2009 - 16:15
Ah! I think I got it. Place those triangles {a, b, c}, {2a, d, c} in a circle with a and 2a as overlapping bases and the c’s as radii. If c^2 – a^2 = b^2 and c^2 – 2a^2 = d^2, then subtract to get a^2 = b^2 – d^2 and thus a^2 + d^2 = b^2. Well that’s clearly impossible, since that would mean that b is simultaneously a line segment leaning from where the two triangles meet to the side of the circle and a necessarily longer segment going straight up from the same point. Impossible! QED
April 14th, 2009 - 19:30
NEVERMIND!!!! A funny thing happens when you square 2a, you get 4a^2 not 2a^2! Back to square one, so to speak.
April 15th, 2009 - 23:06
OKAY, here we go. If {a,b,c} and {2a,d,c} are Pythag. triples, then I’m pretty sure I can get that a must be even and that the triples are primitive.
Well, if you place the corresponding triangles in a circle of radius c standing on their bases, a and 2a, you can see that the sides b, c and d, c extend to chords which cut out arcs, one exactly twice as big as the other. That means the angles opposite a and 2a are in the same ratio, name them O/2 and O.
So, cosO = d/c and cosO/2 = b/c. But by the half angle formula for cosines, cosO/2 = sqrt( (1 + d/c)/2).
Thus, (b/c)^2 = (1 + d/c)/2
2b^2 = c^2 + dc.
This, probably among other things, contradicts that gcd(b,c) = 1.
Note: If a is even, b,c and d are odd.
Also, through manipulation or noticing that if you place the triangles so they overlap with length b crossing exactly midway through the hypotenuse of the other triangle and observing the rule for the products of parts of chords we get eventually: d^2 = 4b^2 – 3c^2.
Substituting the above equation for 2b^2 we get: d^2 = 2dc – c^2.
So, d and c must share factors as well! In fact, it looks like b and d each contain c entirely, but how can that be if it’s the hypotenuse?
I think this direction is the most fruitful route toward clear contradictions.
So, no Chris, there is no Santa Double-Claus.
April 16th, 2009 - 00:17
Ah, no. The arcs are not in the same ratio as their corresponding chords. So, the angle I called O/2 would actually be smaller than that, less than half of angle O, I think. But this general route still may well give a genuine contradiction.
April 17th, 2009 - 10:26
Fascinating question, Chris. It amounts to being able to stack two inscribed rectangles in a circle (of whole number radius) with the same heights and expect whole number lengths. Stacking on a horizontal diameter
We could generalize it to triples of the form {a,b,c}, {na,d,c} and get similarly inscribed rectangles, one with height n -1 times the other.
I suspect that not only would an irrational crop up, but that the big transcendental pi itself would come out to contradict this.
It also amounts to getting that the sinp = a/c, sinq =2a/c, cosp = b/c, cosq = d/c.
May 10th, 2009 - 19:07
get a life Keith!!!!!!!!!!!!!!!
May 14th, 2009 - 07:50
Everyone’s a critic. Ain’t it grand?
My latest thoughts: If there exist Pyth. triples of the form {a, b, c}, {2a, d, c}; and if we can assume (which I think we can) that they are primitive and that the a and 2a can be represented as the even legs in the Euclidean Algorithm, then
{a, b, c} = {n^2 – m^2, 2nm, n^2 + m^2}
{2a, d, c} = {v^2 – u^2, 4nm, n^2 + m^2}.
This implies that (n^2 + m^2)^2 – (4nm)^2 is a square, since it’s root must be v^2 – u^2 (an odd leg).
So, n^4 – 14n^2m^2 + m^4 is a square, while n^4 – 14n^2m^2 + 49m^4 must also be a square, as its a squared binomial.
This corresponds to x^2 – 14x + 1 and x^2 – 14x + 49 being squares, where x = n^2 and m= 1. They differ by 48. The only squares that differ by 48 are 1 and 49, 16 and 64, and 121 and 169, which respectively correspond to n^2 = 0, 15, and 20, none of which are permissible.
Don’t know if this really leads anywhere.
Anyone with knowledge or rumor of a proof, please come forward.
July 29th, 2009 - 16:02
Pythagorean Triples Summary and Clarification:
Regarding the question about whether or not two Pythagorean triples of the form {a,b,c} and {2a,d,c} exist. I don’t think so — still don’t have a proof — but the question leads to lots of interesting questions about squares and rationals.
Let’s assume such triples exist. We can also assume without loss of generality that they are both primitive triples. If we now assume that a is odd, we get a contradiction. Observe:
{a,b,c} = {u^2 – v^2, 2uv, u^2 + v^2}
{2a,d,c} = {2xy, x^2 – y^2, x^2 + y^2}
for some u,v and x,y such that each pair is relatively prime and of opposite parity.
That means 2xy = 2a ⇒ xy = a, which means a is even, since either x or y is even.
Therefore a must be even and
{a,b,c} = {2uv, u^2 – v^2, 2uv, u^2 + v^2}
{2a,d,c} = {2xy, x^2 – y^2, x^2 + y^2}
where 2xy = 4uv and x^2 + y^2 = u^2 + v^2.
From here we get that c – 2a, c – a , c + a, and c + 2a are squares, because these are really
x^2 – 2xy + y^2, u^2 – 2uv + v^2, u^2 + 2uv + v^2, and x^2 + 2xy + y^2
OR (x – y)^2, (u – v)^2, (u + v)^2, and (x + y)^2.
I suspect that no set of squares are spaced out like that. In other words, I seriously doubt that there exist four squares of the form n^2, n^2 + k, n^2 + 3k, and n^2 + 4k. However, that’s just my mathematical intuition. I just don’t think that a parabola or a square root function will bend through those four linearly spaced points without hitting an irrational.
If such triples do exist, though, we would get the following bonus set of triples:
{4m, 4(u^2 – 4uv + v^2) – 1, 4(u^2 – 4uv + v^2) + 1}
{4(u – v), 4(u – v)^2 – 1, 4(u – v)^2 + 1}
{4(u + v), 4(u + v)^2 – 1, 4(u + v)^2 + 1}
{4w, 4(u^2 + 4uv + v^2) – 1, 4(u^2 + 4uv + v^2) + 1}
for m, w that equal the square roots of c – 2a, c + 2a, respectively.
August 15th, 2009 - 02:36
Hello Chris and Keith,
Regarding the question about whether or not two Pythagorean triples of the form {a,b,c} and {2a,d,c} exist.
The obvious way to handle this problem is posing
the question: what have the two triples in common?
Well, the commom thing is the hypotenuse c.
Let us therefore concentrate on c.
What do we know about c?
Can c be a prime number?
No, c cannot be a prime number.(See: If p prime and p=a2+b2 for some a,b then the solution is unique.
http://f2.org/maths/nthproof.html)
So there is a factorisation of c.
Let us assume that c has two factors k and l,so
c=k*l; x^2 + y^2 = k^2 and w^2 + z^2 = l^2.
Now we can apply the identity rules:
(x^2 + y^2)*(w^2 + z^2)=(xw – yz)^2 +(yw + xz)^2
and
(y^2 + x^2)*(w^2 + z^2)=(yw – xz)^2 +(xw + yz)^2
What we have to do now is to show that the triples
{xw-yz,yw+xz,kl} and {yw-xz,xw+yz,kl} cannot be
represented as {a,b,c} and {2a,d,c}
There is more to say, but you may consider to
handle the problem in this manner.
August 15th, 2009 - 18:35
Interesting.
But while it does seem true that triples with prime hypotenuses are singular, we don’t have the situation that p = a^2 + b^2. We have p^2 = a^2 + b^2.
I also don’t know how we would be guaranteed that both k^2 and l^2 are the sums of squares (that both k and l are hypotenuses). Yet, again, it does seem to be true that hypotenuses factor into other hypotenuses.
I’m looking into infinite descent proofs, but I’m very skeptical of them. There exist infinite descent proofs that arithmetic progressions of four squares cannot occur. This is similar to our situation.
Anyway, thanks for the tip. Will look into it.
August 15th, 2009 - 19:14
Oh, of course, we would have p = a^2 + b^2 if c were prime, since c = u^2 + v^2.
So, among the many things we know, we know c is not prime.
But I still need proof that k and l are hypotenuses. And then the rest would have to be worked out.
August 16th, 2009 - 15:44
So many roads to go down. For example, using the fact that (c – a)(c – 2a),
(c – a)(c + 2a), (c + a)(c – 2a), (c + a)(c + 2a) are all squares and the quadratic formula I can get the following triples
{x, a/2, c + 3a/2}, {y, a/2, c – 3a/2}, {r, 3a/2, c + a/2}, {s, 3a/2, c – a/2}
where x^2 = (c + a)(c + 2a), y^2 = (c – a)(c – 2a),
r^2 = (c – a)(c + 2a), s^2 = (c + a)(c – 2a).
All I need is one good contradiction!
August 30th, 2009 - 21:43
LOOKS LIKE WE HAVE OUR PROOF (THANKS TO HENK)!
I buy Henk’s assumptions about the factors of c. They must be primitive hypotenuses as long as they are prime, which we can assume. This has been proven by Euler and the proof can be found in Richard Friedberg’s “An Adventurer’s Guide to Number Theory.”
AND it looks like the identity provides our contradiction! If we assume that x and z are odd, then {xw – yz, yw + xz, kl} and {yw – xz, xw + yz, kl} represent
{a, b, c} and {d, 2a, c}. Therefore a = 2yz = xw – yz. So, 3yz = xw.
This is impossible, since x, y and w,z are relatively prime and x cannot be equal to w or z (nor can y be w or z). Yet if 3yz = xw, then x = 3z. But this forces y = w. Impossible!
Maybe I’m missing something, as I’m coming up with this as I’m writing this submission (which I really shouldn’t be doing!) But this looks like the contradiction I’ve been looking for.
THANKS HENK!!!
PROBLEM RESOLVED?
September 2nd, 2009 - 15:25
BRAVO KEITH, WELL DONE.
The Beauty of Truth is that it is always simple.
You spoke about generalisation, i.e. comparing the
triples {a,b,c} and {na,d,c}.
I have another generalisation in mind, which I have
studied for more than 10 years.
It is the quadratic form ax^2+(2a-1)xy+ay^2=k, where a,k are integers.
When a=1 we get x^2+xy+y^2=k
When a=1/2 we get (1/2)x^2+(1/2)y^2=k
When a=-3 we get -3x^2-7xy-3y^2=k
My problem was:
Let ax1^2+(2a-1)x1x2+ax2^2=k
Let ay1^2+(2a-1)y1y2+ay2^2=l
Is there any z1 and z2 such that
az1^2+(2a-1)z1z2+az2^2=kl
and that z1 and z2 can be written as a function
of a,x1,x2,y1,y2 ?
Yes there is: z1=ax1y1+ax2y1+(a-1)x1y2+ax2y2
z2=-ax1y1-(a-1)x2y1-ax1y2-ax2y2
When a=1 we can multiply ellipses
When a=1/2 we can mutiply circles and form pyth. triples
When a=-3 we can solve Pell’s equations:
-3x^2-7xy-3y^2=1
I have mainly been working on the case a=1 as a basis for solving Fermats Last Theorem
I am planning to create a website and publicate the
results so far.
September 7th, 2009 - 08:49
GOOD LUCK!!
I hope there is a simple fundamental reason why two cubes or hypercubes of the same dimension cannot merge to form another cube or hypercube of that same dimension, all in integer coordinates.
Also I wish that Goedel had come up with a method for determining whether or not a proof could exist for specific conjectures within limited systems, like elementary mathematics.
September 9th, 2009 - 14:19
A NEW QUESTION
Before I come up with my new question, one last
remark about Keith’s proof of the fact that if
{a,b,c} is a triple, then {d,2a,c} is not.
It was shown that if they did exist, it was leading
to a contradiction: “a = 2yz = xw – yz. So, 3yz = xw. This is impossible, since x, y and w,z are relatively prime and x cannot be equal to w or z (nor can y be w or z). Yet if 3yz = xw, then x = 3z. But this forces y = w. Impossible!”
Maybe there are readers of this Blog who ask the
question: why impossible? (It is more a statement
then a proof).
We read in Keith’s comment of 16 aug:
x^2 = (c + a)(c + 2a), y^2 = (c – a)(c – 2a),
meaning: 9z^2=(c + a)(c + 2a), y^2 =(c – a)(c – 2a)
This means x is divisible by 3 and lets assume
(c+a) is divisible by 3. Then (c-2a) is divisible
by 3, which implies y is divisible by 3.
And both x and y cannot be divisible by 3.
And now my question. Or rather 2 questions:
In my last post I wrote:
“When a=-3 we can solve Pell’s equation:
-3x^2-7xy-3y^2=1″
Meaning I wanted to solve -3x^2-7xy-3y^2=1 in integers.
So, lazy as I was, I first asked advice from my
academic formed teachers,how to handle the problem.
They all advised to substitute x=p+q, and y=p-q
which gives q^2-13p^2=1
Why are mathematiciens so eager in their wish to
“simplify” things, even if that means that they
dramatically change the original question?
Question 1) Why is solving -3x^2-7xy-3y^2=1
totally different from solving q^2-13p^2=1 ?
Question 2) Let q^2-Dp^2=1
What can we say about D for q^2-Dp^2=-1 being
solvable. This question is about the negative
Pell’s equation.
September 12th, 2009 - 15:27
Re: My August 30th post
I think I thought I had good reason to assert that neither x nor y could equal to z or w, but i can’t see that reason at all now.
Don’t know if there’s a solid contradiction there after all.
September 15th, 2009 - 05:14
DON’T GIVE UP YET
We have the formula’s:
x^2+y^2=k^2 x=3z
w^2+z^2=l^2 y=w
therefore 9z^2+w^2=k^2 9z^2=k^2-w^
and z^2=l^2-w^2
3^2=5^2-4^2
Further we have the identity formula’s:
(a^2-b^2)(c^2-d^2)=(ac+bd)^2-(bc+ad)^2
(see: http://www.geocities.com/fredlb37/node8.html)
So we have:
9z^2=k^2-w^2 what we can wtite as:
(5^2-4^2)(l^2-w^2)=(5l+4w)^2 – (4l+5w)^2= k^2-w^2
with l>w , k>w and (5l+4w)>(4l+5w)
You have something usefull here??
September 17th, 2009 - 07:43
PROBLEM SOLVED?
I am inclined to think that indeed the identity
formula’s are very usefull in this problem and that we can conclude from my last post:
w=4l+5w , therefore w=-l , therefore k=l and
THAT is impossible !!
Agreed??
By the way, mij last link did not work, because
the last “)” was to close to html , so here is the
link again. Now it should work.
http://www.geocities.com/fredlb37/node8.html
September 28th, 2009 - 05:30
BASIC NUMBER THEORY AND THE NECESSITY OF ACCEPTING NEGATIVE INTEGERS AS OF EQUAL IMPORTANCE
In my post of 02 September 2009 I showed my discovery:
“My problem was:
Let ax1^2+(2a-1)x1×2+ax2^2=k
Let ay1^2+(2a-1)y1y2+ay2^2=l
Is there any z1 and z2 such that
az1^2+(2a-1)z1z2+az2^2=kl
and that z1 and z2 can be written as a function
of a,x1,x2,y1,y2 ?
Yes there is:
z1=ax1y1+ax2y1+(a-1)x1y2+ax2y2
z2=-ax1y1-(a-1)x2y1-ax1y2-ax2y2 ”
For which I claim copyright; and for most things that will follow, unless stated otherwise.
The reason that I choose to publish my discoveries
is the fact that I believe that knowledge should be
public and accessible.
Another reason for publishing is to prevent others
to make mistakes I did.
I must confess that when I did my discovery described above, I realised that I had
defined things (such as multiplying quadratic forms) totally wrong for more than 20 years.
So let’s rock and roll…
Let’s start at the very beginning
A very good place to start:
We will examine the most special ellips:
x^2+xy+y^2=k
Until we finally arrive at Fermat’s Last Theorem.
(It will be a long, long journey…so stay by my
side…when we walk through the storm, maybe I
can be your gide..)
August 18th, 2010 - 09:39
Links below to see the revised version of my paper on ordering the Pythagorean triples by Pellian Sequences (based on Pell-type recursion preserving leg difference):
http://rationalargumentator.com/issue232/PPTs_Pellian.html
http://rationalargumentator.com/issue232/Pellian.pdf
August 18th, 2010 - 09:44
Links below to see the revised version of my paper on ordering the Pythagorean triples by Pellian sequences (based on Pell-type recursion preserving leg difference):
http://rationalargumentator.com/issue232/PPTs_Pellian.html
http://rationalargumentator.com/issue232/Pellian.pdf
August 24th, 2010 - 14:41
Cut and paste the links below to see the revised version of my paper on ordering the Pythagorean triples by Pellian sequences (based on Pell-type recursion preserving leg difference):
rationalargumentator.com/issue232/PPTs_Pellian.html
rationalargumentator.com/issue232/Pellian.pdf
February 25th, 2011 - 14:48
HEY! How about a contest???
Who can either unearth or craft a proof that no pair of Pythagorean triples of the form {a, b, c} and {2a, d, c} exists?
Without loss of generality, I believe, we can safely assume that the triples are primitive and the doubled leg is the even one, ie a is even.
We could extend this to any or all n such that no pair of Pythagorean triples of the form {a, b, c} and {na, d, c} exists.
Whaddayou think???
July 1st, 2011 - 08:19
Full Disclosure: At the time I posted the above challenge a fairly esteemed blogger outlined a proof using the Fibonacci Box method that triples cannot be transformed to get the above result. I argued that I needed more than inability to transform; I needed proof of the impossibility of the existence of the triples above. We agreed to disagree.
But perhaps the blogger is right and there is a proof resting on the use of Fibonacci Boxes and/or Ternary Trees.
October 6th, 2011 - 14:16
We can show that no such pairs of triples exist using Dickson’s Theorem:
______________
THEOREM:
To find integer solutions to x^2 + y^2 = z^2 find positive integers r, s, t
such that r^2 = 2st is a perfect square.
Then: x = r + s, y = r + t, z = r + s + t .
______________
Since by assumption the hypotenuses are the same what you are asking for is:
1) [ x, y, z] where s = (z – x), t = (z – y), r = (z – s – t).
2) [2x, d, z] where s’ = (z – 2x), t’ = (z –d), r’= (z – s’– t’).
This requires that (s + t) = (s’ + t’) , that r = r’ , AND that r^2 = 2st = 2s’t’ .
But since st = s’t’ , we can substitute s for s’ or for t’.
But then s = (z–x) AND s= (z–2x) which is impossible because r , s , t must be positive integers. ( r can not be equal to zero).
see: Dickson’s Method http://en.wikipedia.org/wiki/Formulas_for_generating_Pythagorean_triples#VI.
January 1st, 2012 - 16:50
Just noticed your response.
Why should s + t = s’ + t’?
This means that y = x + d, so the two triples would be
x, x + d, z and 2x, d, z as if the legs have to have the same sum.
This seems too strange to be correct, even given that we’re going for a
contradiction.
January 2nd, 2012 - 14:38
PS The proof I alluded to above (July 1, 2011) using the Fibonacci Box method is
definitely invalid.
January 15th, 2012 - 10:14
I don’t mean to sound so informal above (Jan 1st). I’m very serious and should have written, “Why MUST s + t = s’ + t’ ?” That’s really quite a leap of a constraint that the sums of the legs must be equal while of course assuming the sums of their squares are equal.
June 17th, 2012 - 09:38
Corollaries and conjecture:
If a pair of triples of the form {a,b,c} and {2a,d,c} exist, then it is easy to show that
c – 2a, c -a, c + a and c + 2a are squares. Just look at their forms in Euclid’s algorithm,
given that a must be even (must equal 2mn, c – a = m^2 – 2mn + n^2,
c – 2a = r^2 – 2rs + s^2, etc.)
Let these squares be represented as M^2, N^2, O^2 and P^2. The first and last two
differ by a = N^2 – M^2, and the middle two differ by 2a. So, we can represent them
as M^2, N^2, 3N^2 – 2M^2 and 4N^2 – 3M^2, with M and N odd. It appears from
inspection of tables that when 3N^2 – 2M^2 or 4N^2 – 3M^2 is a square, the other
misses being an odd square by a factor of 8. In other words, either O or P must be irrational, it appears. In still other words, if you take an interval with perfect square
endpoints and advance it by double its length, one of the new endpoints is not a
perfect square; the image of the original interval under the square root function has
integral length, while the image of the new one has irrational length. If this conjecture is proven true, it would suffice in proving that the original triples could not
exist.
Also, if we represent O as N +q and P as N + p, then we get that q^2 + 2Nq over
p^2 + 2Np must equal 2/3. There are some inherent constraints: p and q are even
integers, with p bigger, and N must be greater than or equal to 1/2q^2 + Nq + 1.
If that quotient can never be exactly 2/3 for qualifying entries of p, q and N, then no
such original triples exist.
July 19th, 2012 - 09:44
Th easiest way to identify Pythagorean Triples is to express the equation as (p+q)^2-(p-q)^2. The Pythagorean triple will have pq as an integer squared.
August 27th, 2012 - 08:59
Further to my comment of 19 July 2012, the best way to prove Fermat’s Last Theorem is to recognise that with n an integer greater than 2, the binomial expansion of (p+q)^n- (p-q)^n will only have an nth root if p equals q, so that with p equalling q every term in the binomial expansion will contain p^n or q^n as a common factor, and the other factors will add up to 2^n. For example, for n=3, 6p^3+2p^3 equals 2^3 X p^3. This method could be applied to n=2 which are not Pythagorean Triples apparently overlooked by Andrew Wiles.
September 15th, 2012 - 08:31
You do realize that what you’re saying about p^n and q^n as common factors and the sum of coefficients being 2^n is totally obvious since you’re simply raising 2p = 2q to the power of n?
January 9th, 2013 - 22:40
You copied incorrectly. The area is ALWAYS an EVEN integer.
May 16th, 2013 - 04:08
The quadratic expression (p+q)^2 -(p-q)^2 equals an integer square if p and q have integer square roots. This is how Pythagorean Triples are identified.
May 23rd, 2013 - 10:26
In reply to Keith Raskin’s comment of 15 September 2012, the whole objective of mathematical proof is to reduce the problem to something which is totally obvious. Andrew Wiles and his associates seem to have forgotten this.