(circa 201 – 285 AD)
Diophantus of Alexandria’s name is sometimes Latinized to Diophanti Alexandrini. More is known about him than about his ancient compatriots. He was an outstanding mathematician who influenced the fields of algebra and arithmetic. Today he is famous for inspiring several developments, which include Fermat’s Last Theorem. His most notable publication, Arithmetica, is actually a series of thirteen treatises with a collection of 130 queries that focused on algebraic equations and theory of numbers. Only six of the original thirteen have survived. Although he tried to offer numerical solutions to those problems, his approach seemed arbitrary to a number of modern researchers. Notwithstanding, their influences on both algebra and number theory have been tremendous. His other publication, known simply as The Porisms was lost over the centuries. And despite having not survived, researchers believe that it consisted of three lemmas (or subsidiary theorems) which he referenced in his Arithmetica. Diophantus is credited as the first of the ancient Alexandrian mathematicians (with Greek ancestry) to realize the importance of fractions. It was his use of them in streamlining arithmetic problems that convinced several of his contemporaries to follow suit. He is also credited with being the first to used symbolical expressions in abridging algebraic equations. His influence and contributions led to several concepts, such as: the Diophantine Equations, the Diophantine Approximations, the Erdös-Diophantine Graph, and so on, being named in his honor. He is also the eponym of the Diophantus lunar impact crater: located at the southwestern part of Mare Imbrium.