Royal Society
What organization did Adrien-Marie Legendre join in 1789?
Adrien-Marie Legendre Adrien-Marie Legendre ( ; ; 18 September 1752 – 9 January 1833 ) was a French mathematician who made numerous contributions to mathematics . Well-known and important concepts such as the Legendre polynomials and Legendre transformation are named after him . Life . Adrien-Marie Legendre was born in Paris on 18 September 1752 to a wealthy family . He received his education at the Collège Mazarin in Paris , and defended his thesis in physics and mathematics in 1770 . He taught at the École Militaire in Paris from 1775 to 1780 and at the École Normale from 1795 . At the same time , he was associated with the Bureau des Longitudes . In 1782 , the Berlin Academy awarded Legendre a prize for his treatise on projectiles in resistant media . This treatise also brought him to the attention of Lagrange . The Académie des sciences made Legendre an adjoint member in 1783 and an associate in 1785 . In 1789 , he was elected a Fellow of the Royal Society . He assisted with the Anglo-French Survey ( 1784–1790 ) to calculate the precise distance between the Paris Observatory and the Royal Greenwich Observatory by means of trigonometry . To this end in 1787 he visited Dover and London together with Dominique , comte de Cassini and Pierre Méchain . The three also visited William Herschel , the discoverer of the planet Uranus . Legendre lost his private fortune in 1793 during the French Revolution . That year , he also married Marguerite-Claudine Couhin , who helped him put his affairs in order . In 1795 , Legendre became one of six members of the mathematics section of the reconstituted Académie des Sciences , renamed the Institut National des Sciences et des Arts . Later , in 1803 , Napoleon reorganized the Institut National , and Legendre became a member of the Geometry section . From 1799 to 1812 , Legendre served as mathematics examiner for graduating artillery students at the École Militaire and from 1799 to 1815 he served as permanent mathematics examiner for the École Polytechnique . In 1824 , Legendres pension from the École Militaire was stopped because he refused to vote for the government candidate at the Institut National . His pension was partially reinstated with the change in government in 1828 . In 1831 , he was made an officer of the Légion dHonneur . Legendre died in Paris on 9 January 1833 , after a long and painful illness , and Legendres widow carefully preserved his belongings to memorialize him . Upon her death in 1856 , she was buried next to her husband in the village of Auteuil , where the couple had lived , and left their last country house to the village . Legendres name is one of the 72 names inscribed on the Eiffel Tower . Mathematical work . Abels work on elliptic functions was built on Legendres and some of Gauss work in statistics and number theory completed that of Legendre . He developed , and first communicated to his contemporaries before Gauss , the least squares method which has broad application in linear regression , signal processing , statistics , and curve fitting ; this was published in 1806 as an appendix to his book on the paths of comets . Today , the term least squares method is used as a direct translation from the French méthode des moindres carrés . His major work is Exercices de Calcul Intégral , published in three volumes in 1811 , 1817 and 1819 . In the first volume he introduced the basic properties of elliptic integrals , beta functions and gamma functions , introducing the symbol Γ normalizing it to Γ ( n+1 ) = n! . Further results on the beta and gamma functions along with their applications to mechanics – such as the rotation of the earth , and the attraction of ellipsoids – appeared in the second volume . In 1830 , he gave a proof of Fermats last theorem for exponent which was also proven by Lejeune Dirichlet in 1828 . In number theory , he conjectured the quadratic reciprocity law , subsequently proved by Gauss ; in connection to this , the Legendre symbol is named after him . He also did pioneering work on the distribution of primes , and on the application of analysis to number theory . His 1798 conjecture of the prime number theorem was rigorously proved by Hadamard and de la Vallée-Poussin in 1896 . Legendre did an impressive amount of work on elliptic functions , including the classification of elliptic integrals , but it took Abels stroke of genius to study the inverses of Jacobis functions and solve the problem completely . He is known for the Legendre transformation , which is used to go from the Lagrangian to the Hamiltonian formulation of classical mechanics . In thermodynamics it is also used to obtain the enthalpy and the Helmholtz and Gibbs ( free ) energies from the internal energy . He is also the namesake of the Legendre polynomials , solutions to Legendres differential equation , which occur frequently in physics and engineering applications , e.g . electrostatics . Legendre is best known as the author of Éléments de géométrie , which was published in 1794 and was the leading elementary text on the topic for around 100 years . This text greatly rearranged and simplified many of the propositions from Euclids Elements to create a more effective textbook . Honors . - Foreign Honorary Member of the American Academy of Arts and Sciences ( 1832 ) - The Moon crater Legendre is named after him . - Main-belt asteroid 26950 Legendre is named after him . - Legendre is one of the 72 prominent French scientists who were commemorated on plaques at the first stage of the Eiffel Tower when it first opened . Publications . - Essays - 1782 Recherches sur la trajectoire des projectiles dans les milieux résistants ( prize on projectiles offered by the Berlin Academy ) - Books - Eléments de géométrie , textbook 1794 - Essai sur la Théorie des Nombres 1797-8 ( An VI ) , 2nd ed . 1808 , 3rd ed . in 2 vol . 1830 - Nouvelles Méthodes pour la Détermination des Orbites des Comètes , 1805 - Exercices de Calcul Intégral , book in three volumes 1811 , 1817 , and 1819 - Traité des Fonctions Elliptiques , book in three volumes 1825 , 1826 , and 1830 - Memoires in Histoire de lAcadémie Royale des Sciences - 1783 Sur lattraction des Sphéroïdes homogènes ( work on Legendre polynomials ) - 1784 Recherches sur la figure des Planètes p . 370 - 1785 Recherches danalyse indéterminée p . 465 ( work on number theory ) - 1786 Mémoire sur la manière de distinguer les Maxima des Minima dans le Calcul des Variations p . 7 ( as Legendre ) - 1786 Mémoire sur les Intégrations par arcs dellipse p . 616 ( as le Gendre ) - 1786 Second Mémoire sur les Intégrations par arcs dellipse p . 644 - 1787 Lintégration de quelques équations aux différences Partielles ( Legendre transform ) - In Memoires présentés par divers Savants à la lAcadémie des Sciences de lInstitut de France - 1806 Nouvelle formula pour réduire en distances vraies les distances apparentes de la Lune au Soleil ou à une étoile ( 30–54 ) - 1807 Analyse des triangles tracés sur la surface dun sphéroide ( 130–161 ) - Tome 10 Recherches sur diverses sortes dintégrales défines ( 416–509 ) - 1819 Méthode des moindres carrés pour trouver le milieu le plus probable entre les résultats de différentes observations ( 149–154 ) , Mémoire sur lattraction des ellipsoïdes homogènes ( 155–183 ) - 1823 Recherches sur quelques objets dAnalyse indéterminée et particulièrement sur le théorème de Fermat ( 1–60 ) - 1828 Mémoire sur la détermination des fonctions Y et Z que satisfont à léquation 4 ( X^n-1 ) = ( X-1 ) ( Y^2+-nZ^2 ) , n étant un nombre premier 4i-+1 ( 81–100 ) - 1833 Réflexions sur différentes manières de démontrer la théorie des parallèles ou le théorème sur la somme des trois angles du triangle , avec 1 planche ( 367–412 ) Mistaken portrait . For two centuries , until the recent discovery of the error in 2005 , books , paintings and articles have incorrectly shown a of the obscure French politician Louis Legendre ( 1752–1797 ) as that of the mathematician Legendre . The error arose from the fact that the sketch was labelled simply Legendre and appeared in a book along with contemporary mathematicians such as Lagrange . The only known portrait of Legendre , rediscovered in 2008 , is found in the 1820 book Album de 73 portraits-charge aquarellés des membres de IInstitut , a book of caricatures of seventy-three members of the Institut de France in Paris by the French artist Julien-Léopold Boilly as shown below :