Pierre de Fermat -LRB- ; 17 August 1601 or 1607 \ / 8 -- 12 January 1665 -RRB- 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.
Pierre de Fermat -LRB- 17 aoÃ "t 1601 â '' 12 janvier 1665 -RRB - Ã © tait avocat franÃ § ais au Parlement de Toulouse, dans le sud de la France, et mathÃ © maticien.