# Sophie Germain

**Sophie Germain** was a French mathematician physicist and philosopher.

She was born on the 1 April 1776 at Paris and she died when she was 55 years old on the 27 June 1831 at Paris too .

Sophie Germain was the first and only woman who** demonstrated Fermat’s Last Theorem** or number theory.

**WHAT SHE DID ???**

There aren’t invalid integers x , and z such as : ** x ^{n} + y^{n} = z^{n}** as soon as n is an integer strictly upper to 2.

In case **n = 1**, the equation x^{n} + y^{n} = z^{n} corresponds to the usual addition.

In case **n = 2**, this equation has another infinity of not invalid solutions, the smallest of which is **(3, 4, 5)** : **3 ^{2} + 4^{2 }= 5^{2}**

See also ** Fermat’s Last Theorem**

** **

# Gottfried Wilhelm Leibniz

**Gottfried Wilhelm Leibniz** was born on 1 of july 1646 in Leibzig and died on the 14 of november 1716 in Hanovre.

He wass a German philosopher, scientist, mathematician, logician, diplomat, jurist, librarian and philologist.

General Leiniz rule :

# Pierre de Fermat

**Pierre de Fermat** was a great French mathematician who is given credit for early developments that led to **infinitesimal calculus** (the mathematical study of change).

He is best known for **Fermat’s Last Theorem**, which he described in a note at the margin of a copy of *Diophantus’ Arithmetica*.

In number theory, **Fermat’s Last Theorem** states that no three positive integers **a, b, and c** satisfy the equation :

*a ^{n} + b^{n} = c^{n
}*

for any integer value of n greater than 2.

The cases n = 1 and n = 2 are known to have infinitely many solutions since antiquity.

See also **Sophie Germain**

# John Venn

**John Venn** was an english mathematician, logician and philosopher.

He was born on 4 August 1834 in Kingston-upon-Hull in the Yorkshire.

He died on 4 April 1923.

He is noted for introducing the **Venn diagram** in 1880.

# Fibonacci

**Leonardo Fibonacci** was born in Italy in 1175 and he died in 1250.

He lived in Algeria where he began his education with the mathematics. He popularized the Arabic numerals and algebraic notation.

The** Fibonacci numbers sequence** is a sequence of integers, in which every number is the sum of the previous two. Fibonacci numbers are intimely connected with the **golden ratio φ**.

**Binet’s formula** allows to calculate the terms of Fibonacci’s sequence without using the recursion.

We recognize the golden ratio **φ** and the other root of the equation occurring in this formula :

With these notations, the Binet’s formula becomes :

A short video to learn more (in french) : https://www.youtube.com/watch?v=2f0CVGlYEGQ