Jean Baptiste Fourier

Jean Baptiste Fourier was born March 21 in 1768 in Auxerre. He was educated at the military school in his home town of Auxerre, after having remained there as a teacher, and later, in the years 1796-1798, he taught at the Ecole Polytechnique.

His first works related to algebra. Theorem on the number of real roots of an algebraic equation which lie between these limits, named after the Fourier transform, it was already stated in his lectures in 1796. Its complete solution was obtained only Sturm in 1829.

The main theme of research has been Fourier mathematical physics. In 1807 and 1811 he presented to the Paris Academy of Sciences their first opening on the theory of heat propagation in solids, and in 1822 published "An analytical theory of heat," which played a major role in the subsequent history of mathematics.

It is this paper derived the differential Fourier heat equation and developed a "Fourier method". The basis of this method is the representation of functions by trigonometric Fourier series, which have become an effective and important tool in mathematical physics. His method of separation of variables has been further developed in the works of Poisson Ostrogradskii and other mathematicians of the 19th century.

Fourier made an important contribution to the solution of the dispute about the concept of function, which was attended by prominent mathematicians of the 18th century.

In 1818, Fourier was researching the question of the conditions of applicability of Newton's method of numerical solutions of equations, not knowing about similar results obtained in 1768 by the French mathematician Muraylem. The result of the work of Fourier on numerical methods for solving equations is the "Analysis of certain equations", published posthumously in 1831.

Died Jean Baptiste Fourier May 16 in 1830 in Paris.