Does the Equation a3 + b3 = c3 Have Any Geographical Significance?

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  • Thread starter Thread starter Loren Booda
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Discussion Overview

The discussion revolves around the equation a3 + b3 = c3 and its potential geometrical significance. Participants explore various interpretations, including connections to geometry, calculus, and the implications of Fermat's Last Theorem.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants question whether the equation has any geometrical significance, suggesting analogies to the Pythagorean theorem using area instead of length.
  • Others argue that cubes do not typically arise in geometry, though they may appear in calculus and physics.
  • A participant introduces the concept of using natural numbers and small cubes, referencing Fermat's Last Theorem, which states that no two natural number cubes can sum to another cube.
  • Some participants propose that the equation can be manipulated using cube roots, although others challenge the validity of this approach, asserting that it misrepresents the original problem.
  • There are discussions about the irrelevance of cube roots in solving the equation and the implications of using specific numbers that fit a manipulated version of the equation.
  • Elliptic curves are mentioned as having beautiful geometry associated with cubic plane curves, suggesting a deeper mathematical context.

Areas of Agreement / Disagreement

Participants express a range of views, with no consensus on the geometrical significance of the equation or the validity of manipulating it with cube roots. The discussion remains unresolved regarding the applicability and implications of the equation.

Contextual Notes

There are limitations in understanding the implications of cube roots and the application of Fermat's Last Theorem, as well as the mathematical rigor required to engage with elliptic curves.

  • #31
wasnt there an error in Wiles work too?
 
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  • #32
Bananaman3579 said:
wasnt there an error in Wiles work too?

In the original version, yes. It took a few other mathematicians many months to help Wiles fix the mistakes.
 
  • #33
Loren Booda said:
Thank you, mathwonk.

I believe elliptic curves may be near impossible to solve analytically.

The Wiki article on elliptic curves quotes my old professor, Serge Lang.

Serge Lang RIP.

Wow I am very jealous that you had the opportunity to learn from one of the best! Were you his student at Yale? His textbooks are classics and a mandatory part of any algebraist collection. Was he as good of a teacher as he was an author?
 
  • #34
I would think that if you are going to introduce cubing into the specific equation, then you would need an extra variable as it would effect a higher dimension.

Mainly: a^3+b^3+c^3=d^3
 
  • #35
Good idea, Math Jeans!
 
  • #36
As I understand it, you are looking for values for a,b, and c where
a+b=c AND a^3 + b^3 = c^3

How about this?
a=cube rt 1
b=cube rt 1
c=cube rt 2
 
  • #37
However, it is clearly the case that three cubes can equal a cube. The simplist case is:
3^3+4^3+5^3=6^3

However as a generalization from 3^2+4^2=5^2, it does not seem to stretch very far.
 
  • #38
Code:
3^3+4^3+5^3 = 6^3
1^3+6^3+8^3 = 9^3
6^3+8^3+10^3 = 12^3
2^3+12^3+16^3 = 18^3
9^3+12^3+15^3 = 18^3
3^3+10^3+18^3 = 19^3
7^3+14^3+17^3 = 20^3
12^3+16^3+20^3 = 24^3
4^3+17^3+22^3 = 25^3
3^3+18^3+24^3 = 27^3
18^3+19^3+21^3 = 28^3
11^3+15^3+27^3 = 29^3
15^3+20^3+25^3 = 30^3
4^3+24^3+32^3 = 36^3
18^3+24^3+30^3 = 36^3
6^3+20^3+36^3 = 38^3
14^3+28^3+34^3 = 40^3
2^3+17^3+40^3 = 41^3
6^3+32^3+33^3 = 41^3
21^3+28^3+35^3 = 42^3
16^3+23^3+41^3 = 44^3
5^3+30^3+40^3 = 45^3
3^3+36^3+37^3 = 46^3
27^3+30^3+37^3 = 46^3
24^3+32^3+40^3 = 48^3
8^3+34^3+44^3 = 50^3
29^3+34^3+44^3 = 53^3
6^3+36^3+48^3 = 54^3
12^3+19^3+53^3 = 54^3
27^3+36^3+45^3 = 54^3
36^3+38^3+42^3 = 56^3
9^3+30^3+54^3 = 57^3
15^3+42^3+49^3 = 58^3
22^3+30^3+54^3 = 58^3
21^3+42^3+51^3 = 60^3
30^3+40^3+50^3 = 60^3
7^3+42^3+56^3 = 63^3
33^3+44^3+55^3 = 66^3
22^3+51^3+54^3 = 67^3
36^3+38^3+61^3 = 69^3
7^3+54^3+57^3 = 70^3
14^3+23^3+70^3 = 71^3
8^3+48^3+64^3 = 72^3
34^3+39^3+65^3 = 72^3
36^3+48^3+60^3 = 72^3
12^3+51^3+66^3 = 75^3
38^3+43^3+66^3 = 75^3
12^3+40^3+72^3 = 76^3
31^3+33^3+72^3 = 76^3
39^3+52^3+65^3 = 78^3
28^3+56^3+68^3 = 80^3
9^3+54^3+72^3 = 81^3
25^3+48^3+74^3 = 81^3
4^3+34^3+80^3 = 82^3
12^3+64^3+66^3 = 82^3
19^3+60^3+69^3 = 82^3
28^3+53^3+75^3 = 84^3
42^3+56^3+70^3 = 84^3
54^3+57^3+63^3 = 84^3
50^3+61^3+64^3 = 85^3
20^3+54^3+79^3 = 87^3
26^3+55^3+78^3 = 87^3
33^3+45^3+81^3 = 87^3
38^3+48^3+79^3 = 87^3
21^3+43^3+84^3 = 88^3
25^3+31^3+86^3 = 88^3
32^3+46^3+82^3 = 88^3
17^3+40^3+86^3 = 89^3
10^3+60^3+80^3 = 90^3
25^3+38^3+87^3 = 90^3
45^3+60^3+75^3 = 90^3
58^3+59^3+69^3 = 90^3
6^3+72^3+74^3 = 92^3
54^3+60^3+74^3 = 92^3
32^3+54^3+85^3 = 93^3
15^3+50^3+90^3 = 95^3
19^3+53^3+90^3 = 96^3
48^3+64^3+80^3 = 96^3
45^3+69^3+79^3 = 97^3
11^3+66^3+88^3 = 99^3
16^3+68^3+88^3 = 100^3
35^3+70^3+85^3 = 100^3
. . .
 
  • #39
However as a generalization from 3^2+4^2=5^2, it does not seem to stretch very far.

What I meant is that I know of no cases where four 4th powers equal a fourth power, let alone in consecutive integers.

Euler's Conjecture is that it took n nth powers to equal an an nth power. But it was shown in 1966--largely by accidential discovery that four fifth powers will do:

27^5+84^5+110^5+135^5 = 144^5.
 
  • #40
robert Ihnot said:
Euler's Conjecture is that it took n nth powers to equal an an nth power. But it was shown in 1966--largely by accidential discovery that four fifth powers will do:

27^5+84^5+110^5+135^5 = 144^5.

No it doesn't.
 
  • #42
Oh, now it does...
 
  • #43
The earlier confusion about the cube rooting, I think you have it wrong.

You have

a3 + b3 = c3

To cube root 'a', you are effectively multiplying it by a1/3 , to do this you would have to also multiply b and c by a1/3. Doing the same for b and c, you'd end up with an equation looking like this:

ab1/3c1/3 + ba1/3c1/3 = ca1/3b1/3
 
  • #44
TimGrebin said:
The earlier confusion about the cube rooting, I think you have it wrong.

You have

a3 + b3 = c3

To cube root 'a', you are effectively multiplying it by a1/3 , to do this you would have to also multiply b and c by a1/3. Doing the same for b and c, you'd end up with an equation looking like this:

ab1/3c1/3 + ba1/3c1/3 = ca1/3b1/3

This isn't right
a^{1\over 3} = (-b^3+c^3)^{1\over 9}
 
  • #45
Good point.
 
  • #46
(11/3)3 + (11/3)3 = (21/3)3

Why won't that work?
 
  • #47
iamafigment said:
(11/3)3 + (11/3)3 = (21/3)3

Why won't that work?
This does work.

iamafigment said:
As I understand it, you are looking for values for a,b, and c where
a+b=c AND a^3 + b^3 = c^3

How about this?
a=cube rt 1
b=cube rt 1
c=cube rt 2
This doesn't work.
 
  • #48
I have heard of this referred to as Pythagora's second theorem. It is said to be one of the most difficult and yet unsolved math problems known. It is stated, A cubed plus B cubed cannot equal C cubed and finding the proof for this has eluded the best mathematicians for centuries. According to lore, Pythagoras had the proof written down on a corner of a papyrus but some how the corner went missing. Props to anyone who can find it. I believe some think it may have to do with a Torus Knot.
 
  • #49
Already got a proof for a more general case - see Fermat's Last Theorem.
 
  • #50
disscombobila said:
I have heard of this referred to as Pythagora's second theorem. It is said to be one of the most difficult and yet unsolved math problems known. It is stated, A cubed plus B cubed cannot equal C cubed and finding the proof for this has eluded the best mathematicians for centuries. According to lore, Pythagoras had the proof written down on a corner of a papyrus but some how the corner went missing. Props to anyone who can find it. I believe some think it may have to do with a Torus Knot.

As was said above, the problem has been solved (for quite some time). The lore you refer to involves Fermat, not Pythagoras.
 
  • #51
Search "Andrew Wiles."
 
  • #53
Hi guys this proof does exist beyond any reason of doubt and it proves itself.

a^n+b^n=c^n rings true as well. Obviously i cannot divulge much about this but WC was stabbing in the wrong direction as such.

as mentioned the proof proves itself.

The only thing WC got right was that it is a curve.

Hopefully i find the right place to publish one day but till then my safe is a good place as my Son and I had painstakingly worked our own logbook on this making it a mathematical equation that works and applies to modern maths.

Oh b t w you use fractions as well in the nth root as it is a great necessity.

Ian
 
Last edited:
  • #54
iansinclair said:
Hi guys this proof does exist beyond any reason of doubt and it proves itself.

a^n+b^n=c^n rings true as well. Obviously i cannot divulge much about this but WC was stabbing in the wrong direction as such.

as mentioned the proof proves itself.

The only thing WC got right was that it is a curve.

Hopefully i find the right place to publish one day but till then my safe is a good place as my Son and I had painstakingly worked our own logbook on this making it a mathematical equation that works and applies to modern maths.

Oh b t w you use fractions as well in the nth root as it is a great necessity.

Ian


LOL what? I can tell you are a mathematician when you say things like "the proof proves itself"

w t f does that even mean.. i don't even?
 
  • #55
This thread is done.
 

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