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

  • Thread starter Loren Booda
  • Start date
In summary, the conversation discusses the geometrical significance of the equation a3 + b3 = c3, where a, b, and c are constants. Some suggest using the Pythagorean theorem with area instead of length, while others mention cubes and spheres in geometry. The conversation also explores the possibility of finding a solution to the equation, but it is ultimately deemed unsolvable according to Fermat's last theorem.
  • #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
 
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  • #37
However, it is clearly the case that three cubes can equal a cube. The simplist case is:
[tex]3^3+4^3+5^3=6^3[/tex]

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:

[tex] 27^5+84^5+110^5+135^5 = 144^5.[/tex]
 
  • #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:

[tex] 27^5+84^5+110^5+135^5 = 144^5.[/tex]

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
[tex] a^{1\over 3} = (-b^3+c^3)^{1\over 9} [/tex]
 
  • #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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