## Mathematicians Of The Day

### 15th June

On this day in 1641, in a letter to Bernard Frenicle de Bessy, Fermat called the theorem that every prime of the form 4

*n*+ 1 is the sum of two squares, the*fundamental theorem of right triangles*. He stated that he had a proof that was "irrefutable". Later he suggested he had a proof by infinite descent. Euler is credited with the first correct proof of the theorem, still called Fermat's theorem.
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##### Born:

- 1640: Bernard Lamy Ⓟ
- 1884: William Watson Ⓟ
- 1894: Nikolai Chebotaryov Ⓟ
- 1906: Gordon Welchman Ⓟ
- 1933: Moshe Carmeli Ⓟ

##### Died:

- 1938: Hans Fitting Ⓟ

#### Quotation of the day

##### From Bernard Lamy

A discourse is beautiful when it is composed according to the Rules of Art; it is great when it is more than ordinary perspicuous; when there is not one equivocation; no sentence unintelligible; no expression ambiguous; when it is well-disposed, and the mind of the Reader led directly to the end of the design, without the remora or impediment of impertinent words. Such clearness like a Torch dispels all obscurity and makes every thing visible.