What is "diophantus"

Diophantus of Alexandria (; born probably sometime between AD 201 and 215; died aged 84, probably sometime between AD 285 and 299), sometimes called "the father of algebra", was an Alexandrian Greek mathematician and the author of a series of books called Arithmetica, many of which are now lost. These texts deal with solving algebraic equations. While reading Claude Gaspard Bachet de Méziriac's edition of Diophantus' Arithmetica, Pierre de Fermat concluded that a certain equation considered by Diophantus had no solutions, and noted in the margin without elaboration that he had found "a truly marvelous proof of this proposition," now referred to as Fermat's Last Theorem. This led to tremendous advances in number theory, and the study of Diophantine equations ("Diophantine geometry") and of Diophantine approximations remain important areas of mathematical research. Diophantus coined the term παρισότης (parisotes) to refer to an approximate equality. This term was rendered as adaequalitas in Latin, and became the technique of adequality developed by Pierre de Fermat to find maxima for functions and tangent lines to curves. Diophantus was the first Greek mathematician who recognized fractions as numbers; thus he allowed positive rational numbers for the coefficients and solutions. In modern use, Diophantine equations are usually algebraic equations with integer coefficients, for which integer solutions are sought. Diophantus also made advances in mathematical notation.

Diophantus is a lunar impact crater that lies in the southwestern part of the Mare Imbrium. It forms a pair with the larger crater Delisle to the north. Diophantus has a wide inner wall and a low central rise. To the north of Diophantus is the sinuous rille designated Rima Diophantus, named after the crater. There is a tiny craterlet near the exterior of the southwest wall.

Diophantus , son of Asclepiodorus, of Sinope, was a general in the service of Mithridates VI of Pontus. Diophantus was active in Mithridates' campaigns in the Bosporan Kingdom and elsewhere around the Black Sea, although their chronology is disputed. An inscription found during the excavations in Chersonesos glorifies Diophantus as "the first foreign invader to conquer the Scythians".

During his first Crimean expedition, he relieved the siege of Chersonesos by the Scythian king Palacus and subdued his allies, the Tauri. He finished this campaign at Scythian Neapolis. During the second campaign, Diophantus checked another invasion of the Scythians, who had joined their forces with the Rhoxolanoi under Tasius. At one point during these campaigns he established a stronghold at Eupatorium on the eastern shore of the Crimea.

Around 107 BC, Mithridates dispatched Diophantes to Panticapaeum with the task of persuading the Bosporan king Paerisades V to cede his kingdom to Mithridates. While he was in the city, the Scythians, led by a certain Saumacus, revolted and killed Paerisades, while Diophantes barely managed to escape to Chersonesos. Back in Pontus, Diophantes rallied his forces and sailed to Crimea with a large fleet. The Scythian uprising was put down and the Bosporan kingdom was reduced to a dependency of Pontus.