Pierre de Fermat was a French lawyer at the Parlement of Toulouse, France, and an amateur mathematician who is given credit for early developments that led to infinitesimal calculus, including his adequality. In particular, he is recognized for his discovery of an original method of finding the greatest and the smallest ordinates of curved lines, which is analogous to that of the then unknown differential calculus, and his research into number theory. He made notable contributions to analytic geometry, probability, and optics. He is best known for Fermat's Last Theorem, which he described in a note at the margin of a copy of Diophantus' Arithmetica.

Born --August 17, 1601Beaumont-de-Lomagne, France

Died --January 12, 1665 (aged 63)

Castres, France

Residence France

Nationality French

Fields--- Mathematics and Law

Known for ---Number theory

Analytic geometry

Fermat's principle

Probability

Fermat's Last Theorem

Influences -----François Viète