Fibonacci, Leonardo

Fibonacci, Leonardo (lāōnär`dō fēbōnät`chē), b. c.1170, d. after 1240, Italian mathematician, known also as Leonardo da Pisa. In Liber abaci (1202, 2d ed. 1228), for centuries a standard work on algebra and arithmetic, he advocated the adoption of Arabic notation. In Practica geometriae (1220) he organized and extended the material then known in geometry and trigonometry. The sequence of numbers 0, 1, 1, 2, 3, 5, 8, 13, 21, … , formed by adding consecutive members, is named for him; it occurs in higher mathematics in various connections. Baldassare Boncompagni edited his works (2 vol., 1857–62).

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Fibonacci, Leonardo 

(also Leonardo of Pisa). Born circa 1170; died after 1228. Italian mathematician.

Traveling in the East, Fibonacci became acquainted with the achievements of Arab mathematicians and made them known to the West. His principal works were Liber abaci (1202)—a treatise on arithmetic (Hindu numbers, Fibonacci numbers) and algebra (up to quadratic equations inclusively)—and Practica geometriae (1220). These are the first works to contain problems involving the application of algebra to geometry.