Jacques Philippe Marie Binet

Jacques Philippe Marie Binet (1786 to 1856) was a French mathematician, physicist and astronomer, born in Rennes and died in Paris. He graduated from the École Polytechnique in 1806, returned there to teach in 1807 and rose to inspector of studies in 1816, a post he lost in 1830 when the new king Louis-Philippe dismissed him. In 1823 he succeeded Delambre in the chair of astronomy at the Collège de France, and he was elected to the Académie des Sciences in 1843. He contributed to number theory and to the foundations of matrix algebra, and is credited as the first to describe the rule for multiplying matrices, in 1812. Binet's formula, which gives the Fibonacci numbers in closed form, is named for him, although Abraham de Moivre knew the result a century earlier.