Fermat's Last Theorem

**Fermat's Last Theorem** or **FLT** is a very famous idea in mathematics. It says that:

- If  is a whole number larger than 2, then the equation  has no solutions when _x_, _y_ and _z_ are natural numbers.

Or,
- It is impossible to express in whole numbers two cubes, which added equal a third cube. Furthermore, it is impossible with anything higher than squares.

This means that there are no examples where ,  and  are natural numbers, i.e. whole numbers larger than zero, and where  is a whole number bigger than 2. Pierre de Fermat wrote about it in 1637 inside his copy of a book called _Arithmetica_. He said "I have a proof of this theorem, but there is not enough space in this margin to write it". However, no correct proof was found for 357 years. It was finally proven in 1995. Most mathematicians do not think that Fermat really had a proof of this theorem.

In its original the problem is as follows:

_Cubum autem in duos cubos, aut quadratoquadratum in duos
_quadratoquadratos & generaliter nullam in infinitum ultra quadratum
_potestatem in duos eiusdem nominis fas est dividere cuius rei
_demonstrationem mirabilem sane detexi. Hanc marginis exiguitas non caperet._

## Overview

Fermat's Last Theorem is an expansion of the Pythagorean theorem, which is an equation that says:
when  are sides of a right triangle. When ,  and  are whole numbers this is called a "Pythagorean triple".

For example, , and since  we can say  is a Pythagorean triple. Fermat's Last Theorem rewrites this as
where  is any natural number.

and claims that, if you make the  bigger than 2, then ,  and  cannot all be natural numbers. For example,  and , and so  fits the theorem.

## Proof

The proof was made for _some'' values of , such as , ,  and , which was done by many mathematicians including Fermat, Euler, Sophie Germain. However, since there are an infinite number of Pythagorean triples, as numbers count upwards forever, this made Fermat's Last Theorem hard to prove or disprove; the full proof must show that the equation has **no** solution for all values of  (when  is a whole number bigger than 2) but it is not possible to simply check every combination of numbers if they continue forever.

An English mathematician named Andrew Wiles found a solution in 1995, 358 years after Fermat wrote about it. Richard Taylor helped him find the solution . The proof took eight years of research. He proved the theorem by first proving the modularity theorem, which was then called the TaniyamaShimura conjecture. Using Ribet's Theorem, he was able to give a proof for Fermat's Last Theorem.  He received the Wolfskehl Prize from Göttingen Academy in June 1997: it amounted to about $50,000 U.S. dollars.

After a few years of debate, people agreed that Andrew Wiles had solved the problem. Andrew Wiles used a lot of modern mathematics and even created new maths when he made his solution. This mathematics was unknown when Fermat wrote his famous note saying that he had a proof, so we think that Fermat did not have a correct proof or he did not have one at all.

### Criticism of proof

Vos Savant wrote in 1995, that Wiles' proof should be rejected for its use of non-Euclidean geometry. She said, "the chain of proof is based in hyperbolic (Lobachevskian) geometry", and because this geometry allows things like squaring the circle, a "famous impossibility" despite being possible in hyperbolic geometry, then "if we reject a hyperbolic method of squaring the circle, we should also reject a hyperbolic proof of Fermat's last theorem."

### Proof without elliptic

Where n is known to sum two ordinal values, it cannot exceed the counted value 2 if the larger is taken as 1 unit.

### BBC Show

There is a show available on the BBC about Fermat's Last Theorem.

## Generalization

Beal's Generalization Conjecture, or the Beal Conjecture, posed by investor Andrew Beal, asks why there are always common factors (like cells in batteries), in equations like this, of the general form
aˣ+bʸ=cᶻ.