Joseph Louis LAGRANGE (Lagrange Joseph Louis)( mathematician and engineer)
Comments for Joseph Louis LAGRANGE (Lagrange Joseph Louis)
Biography Joseph Louis LAGRANGE (Lagrange Joseph Louis)


(17361813)
The scientific activity of one of the greatest mathematicians and engineers XVIII century Lagrange extremely rich discoveries, while his life was poor in highprofile events, although it accounts for a very turbulent period in European history. He had poor health, was characterized by great modesty and delicacy. Lagrange carefully studied the work of predecessors, subjecting them to critical analysis, refinement and improvement. Born Joseph Louis Lagrange in Turin (Kingdom of Sardinia in Italy), his ancestors came from France. At the request of his father's 14yearold La Grange entered the University of Turin to study law, but became interested in mathematics and, along with the works of Julius Caesar and Cicero's acquaintance with the works of Newton and Halley.
. Autumn 1755 Lagrange, . And he was at that time only 19 years old, . was promoted to associate professor of mathematics at the artillery school of Turin, together with his students, he founded the Turin scientific society, . transformed after the Turin Academy of Sciences, . In Turin collection for the years 17601761 Lagrange published article, which opened a new stage in the development of the calculus of variations. In 1756, on the recommendation of Euler, Lagrange which was already well acquainted by correspondence (which lasted intermittently from 1754 th to 1775 years), twentymathematician, was elected a foreign member of the Berlin Academy of Sciences. And ten years later, again by Euler's proposal, supported by D'Alembert, Lagrange gets a place that before his departure to Russia he held a famous scientist  the director of the mathematical class of the Berlin Academy of Sciences (17661787). In its walls 'vital spirit of Euler', here lay the pile of his manuscripts  the source of new ideas and methods for the Lagrange. He closely followed the printing of these works in 'Memoirs of the Berlin Academy of Sciences'.
. An anchor Lagrange was a French mathematician and philosopher D'Alembert  they met in Paris in 1763.
. Lagrange studied mechanics, celestial mechanics, algebra, number theory, and issues of vibration of the string, the rationale of the infinitesimal calculus . In 'Reflections on the algebraic solution of equations' (1771  1772) he, in particular, tried to find common ways to solve equations of any degree of whole. These studies have helped Evariste Galois to develop its future theory. Unfortunately, the brilliant French mathematician died in a duel at 21.
. Ending the Euler Lagrange substantiate that an integer can be represented as the sum of four squares, and Euler CPADhu also gave another proof of this theorem . In 1774 in Lyon, was published French translation of 'Universal arithmetic' with the important additions Euler Lagrange. In 1787, Grange moved to Paris, where for the next year issued a prepared in Berlin 'Analytical Mechanics'  fundamental work, completion of the development of this science in the XVIII century. He has compiled methods for solving problems of mechanics to the general formula that allows us to find solutions to any specific problems.
These were the tumultuous years of revolution and war. What was not had to deal with Lagrange: chemistry, . that ballistics, . that studies the motion of the projectile inside the barrel, . calculate the explosive force of gunpowder, . be in charge of finances of the country, . work on the commission for the introduction of the decimal system of weights and measures, . together with other scientists to participate in the organization of the Polytechnic and normal schools (higher education), . and then teach there, . Lectures laywhether based books, which gave rise to many areas of mathematics.
As noted by our renowned naval architect and mathematician, Academician AN Krylov, 'time  the best criterion for all human affairs'. As demonstrated over the years? Methods 'Analytical Mechanics' Lagrange become a powerful mediastvom engineering calculations in the construction of railways and bridges made it possible to create a gyroscopic compass and solve the problem of rotation of the projectile. Lagrange's formula helped research the French scientist U. Le Verrier, epochmaking in the practice of celestial mechanics. Recall that the calculations by the German astronomer Le Verrier I. Galle found a new planet  Neptune.
. 'Laplace and Lagrange, we required knowledge of, . not only in the near future, . but for many millions of years in the future, no Earth, . no other planets in general are not threatened by death in the scorching sun vortices, . nor slow agony in the icy depths of interstellar space have given ', .  Wrote a famous historian of astronomy B.A.VorontsovVelyaminov.,
. And now scientific thought often moves in directions indicated by Lagrange . His name does not descend from the pages of modern textbooks on higher mathematics and mechanics: Lagrange series, . Lagrange interpolation formula, . remainder of the Taylor series in the form of Lagrange, . equation in the form of Lagrange, . method of variation of arbitrary constants Lagrange, etc.,
. He was elected a foreign member of several academies (including the Paris and St. Petersburg) . His ideas were developed, many mathematics and mechanics, including KF Gauss, PG Dirichlet, Chebyshev, AM Legendre, C. G. J. Jacobi and others.
