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Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMAugustin-Louis CauchyFrom Wikipedia, the free encyclopediaBaron Augustin-LouisCauchy (French: [oɡystɛ̃lwi koʃi]; 21 August 1789– 23 May 1857) was aFrench mathematicianwho was an earlypioneer of analysis. Hestarted the project offormulating and provingthe theorems ofinfinitesimal calculus in arigorous manner,rejecting the heuristicprinciple of thegenerality of algebraexploited by earlierauthors. He definedcontinuity in terms ofinfinitesimals and gaveseveral importanttheorems in complexanalysis and initiated thestudy of permutationgroups in abstractalgebra. A profoundmathematician, Cauchyexercised a greathttp://en.wikipedia.org/wiki/Augustin-Louis CauchyAugustin-Louis CauchyCauchy around 1840. Lithography by ZéphirinBelliard after a painting by Jean Roller.Born21 August 1789Paris, FranceDied23 May 1857 (aged 67)Sceaux, nsÉcole Centrale du PanthéonÉcole Nationale des Ponts etChausséesÉcole polytechniqueAlma materÉcole Nationale des Ponts etChausséesPage 1 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMDoctoralFrancesco Faà di Brunoinfluence over hisstudentsViktor Bunyakovskycontemporaries andKnown forSee listsuccessors. His writingscover the entire range ofmathematics and mathematical physics."More concepts and theorems have been named for Cauchy than forany other mathematician (in elasticity alone there are sixteen conceptsand theorems named for Cauchy)."[1] Cauchy was a prolific writer; hewrote approximately eight hundred research articles and five completetextbooks. He was a devout Roman Catholic, strict Bourbon royalist,and a close associate of the Jesuit order.Contents1 Biography1.1 Youth and education1.2 Engineering days1.3 Professor at École Polytechnique1.4 In exile1.5 Last years2 Work2.1 Early work2.2 Wave theory, mechanics, elasticity2.3 Number theory2.4 Complex functions2.5 Cours d'Analyse2.6 Taylor's theorem2.7 Argument principle, stability2.8 Outputhttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 2 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PM3 Politics and religious beliefs4 See also5 Notes6 References7 Further reading8 External linksBiographyYouth and educationCauchy was the son of Louis François Cauchy (1760–1848) andMarie-Madeleine Desestre. Cauchy had two brothers, AlexandreLaurent Cauchy (1792–1857), who became a president of a division ofthe court of appeal in 1847, and a judge of the court of cassation in1849; and Eugene François Cauchy (1802–1877), a publicist who alsowrote several mathematical works.Cauchy married Aloise de Bure in 1818. She was a close relative ofthe publisher who published most of Cauchy's works. By her he hadtwo daughters, Marie Françoise Alicia (1819) and Marie Mathilde(1823).Cauchy's father (Louis François Cauchy) was a high official in theParisian Police of the New Régime. He lost his position because of theFrench Revolution (July 14, 1789) that broke out one month beforeAugustin-Louis was born.[2] The Cauchy family survived the revolutionand the following Reign of Terror (1794) by escaping to Arcueil, whereCauchy received his first education, from his father. After theexecution of Robespierre (1794), it was safe for the family to return tohttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 3 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMParis. There Louis-François Cauchy found himself a new bureaucraticjob, and quickly moved up the ranks. When Napoleon Bonaparte cameto power (1799), Louis-François Cauchy was further promoted, andbecame Secretary-General of the Senate, working directly underLaplace (who is now better known for his work on mathematicalphysics). The famous mathematician Lagrange was also no strangerin the Cauchy family.On Lagrange's advice, Augustin-Louis was enrolled in the ÉcoleCentrale du Panthéon, the best secondary school of Paris at that time,in the fall of 1802. Most of the curriculum consisted of classicallanguages; the young and ambitious Cauchy, being a brilliant student,won many prizes in Latin and Humanities. In spite of these successes,Augustin-Louis chose an engineering career, and prepared himself forthe entrance examination to the École Polytechnique.In 1805 he placed second out of 293 applicants on this exam, and hewas admitted. One of the main purposes of this school was to givefuture civil and military engineers a high-level scientific andmathematical education. The school functioned under militarydiscipline, which caused the young and pious Cauchy some problemsin adapting. Nevertheless, he finished the Polytechnique in 1807, atthe age of 18, and went on to the École des Ponts et Chaussées(School for Bridges and Roads). He graduated in civil engineering,with the highest honors.Engineering daysAfter finishing school in 1810, Cauchy accepted a job as a juniorengineer in Cherbourg, where Napoleon intended to build a navalbase. Here Augustin-Louis stayed for three years, and although hehad an extremely busy managerial job, he still found time to preparehttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 4 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMthree mathematical manuscripts, which he submitted to the PremièreClasse (First Class) of the Institut de France.[3] Cauchy's first twomanuscripts (on polyhedra) were accepted; the third one (ondirectrices of conic sections) was rejected.In September 1812, now 23 years old, after becoming ill fromoverwork, Cauchy returned to Paris. Another reason for his return tothe capital was that he was losing his interest in his engineering job,being more and more attracted to the abstract beauty of mathematics;in Paris, he would have a much better chance to find a mathematicsrelated position. Although he formally kept his engineering position, hewas transferred from the payroll of the Ministry of the Marine to theMinistry of the Interior. The next three years Augustin-Louis wasmainly on unpaid sick leave, and spent his time quite fruitfully, workingon mathematics (on the related topics of symmetric functions, thesymmetric group and the theory of higher-order algebraic equations).He attempted admission to the First Class of the Institut de France butfailed on three different occasions between 1813 and 1815. In 1815Napoleon was defeated at Waterloo, and the newly installed Bourbonking Louis XVIII took the restoration in hand. The Académie desSciences was re-established in March 1816; Lazare Carnot andGaspard Monge were removed from this Academy for politicalreasons, and the king appointed Cauchy to take the place of one ofthem. The reaction by Cauchy's peers was harsh; they considered hisacceptance of membership of the Academy an outrage, and Cauchythereby created many enemies in scientific circles.Professor at École PolytechniqueIn November 1815, Louis Poinsot, who was an associate professor atthe École Polytechnique, asked to be exempted from his s CauchyPage 5 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMduties for health reasons. Cauchy was by then a rising mathematicalstar, who certainly merited a professorship. One of his greatsuccesses at that time was the proof of Fermat's polygonal numbertheorem. However, the fact that Cauchy was known to be very loyal tothe Bourbons, doubtless also helped him in becoming the successor ofPoinsot. He finally quit his engineering job, and received a one-yearcontract for teaching mathematics to second-year students of theÉcole Polytechnique. In 1816, this Bonapartist, non-religious schoolwas reorganized, and several liberal professors were fired; thereactionary Cauchy was promoted to full professor.When Cauchy was 28 years old, he was still living with his parents. Hisfather found it high time for his son to marry; he found him a suitablebride, Aloïse de Bure, five years his junior. The de Bure family wereprinters and booksellers, and published most of Cauchy's works.[4]Aloïse and Augustin were married on April 4, 1818, with great RomanCatholic pomp and ceremony, in the Church of Saint-Sulpice. In 1819the couple's first daughter, Marie Françoise Alicia, was born, and in1823 the second and last daughter, Marie Mathilde.[5] Cauchy had twobrothers: Alexandre Laurent Cauchy, who became a president of adivision of the court of appeal in 1847, and a judge of the court ofcassation in 1849; and Eugène François Cauchy, a publicist who alsowrote several mathematical works.The conservative political climate that lasted until 1830 suited Cauchyperfectly. In 1824 Louis XVIII died, and was succeeded by his evenmore reactionary brother Charles X. During these years Cauchy washighly productive, and published one important mathematical treatiseafter another. He received cross appointments at the Collège deFrance, and the Faculté des Sciences of the ouis CauchyPage 6 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMIn exileIn July 1830 France underwent another revolution. Charles X fled thecountry, and was succeeded by the non-Bourbon king Louis-Philippe(of the House of Orléans). Riots, in which uniformed students of theÉcole Polytechnique took an active part, raged close to Cauchy'shome in Paris.These events marked a turning point in Cauchy's life, and a break inhis mathematical productivity. Cauchy, shaken by the fall of thegovernment, and moved by a deep hatred of the liberals who weretaking power, left Paris to go abroad, leaving his family behind. Hespent a short time at Fribourg in Switzerland, where he had to decidewhether he would swear a required oath of allegiance to the newregime. He refused to do this, and consequently lost all his positions inParis, except his membership of the Academy, for which an oath wasnot required. In 1831 Cauchy went to the Italian city of Turin, and aftersome time there, he accepted an offer from the King of Sardinia (whoruled Turin and the surrounding Piedmont region) for a chair oftheoretical physics, which was created especially for him. He taught inTurin during 1832–1833. In 1831, he had been elected a foreignmember of the Royal Swedish Academy of Sciences.In August 1833 Cauchy left Turin for Prague, to become the sciencetutor of the thirteen-year-old Duke of Bordeaux Henri d'Artois (1820–1883), the exiled Crown Prince and grandson of Charles X. As aprofessor of the École Polytechnique, Cauchy had been a notoriouslybad lecturer, assuming levels of understanding that only a few of hisbest students could reach, and cramming his allotted time with toomuch material. The young Duke had neither taste nor talent for eithermathematics or science, so student and teacher were a perfecthttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 7 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMmismatch. Although Cauchy took his mission very seriously, he didthis with great clumsiness, and with surprising lack of authority overthe Duke.During his civil engineering days, Cauchy once had been briefly incharge of repairing a few of the Parisian sewers, and he made themistake of telling his pupil this; with great malice, the young Duke wentabout saying that Mister Cauchy started his career in the sewers ofParis. His role as tutor lasted until the Duke became eighteen yearsold, in September 1838. Cauchy did hardly any research during thosefive years, while the Duke acquired a lifelong dislike of mathematics.The only good that came out of this episode was Cauchy's promotionto Baron, a title that Cauchy set great store by. In 1834, his wife andtwo daughters moved to Prague, and Cauchy was finally reunited withhis family, after four years of exile.Last yearsCauchy returned to Paris and his position at the Academy of Scienceslate in 1838. He could not regain his teaching positions, because hestill refused to swear an oath of allegiance. However, he desperatelywanted to regain a formal position in Parisian science.In August 1839 a vacancy appeared in theBureau des Longitudes. This Bureau hadsome resemblance to the Academy; forinstance, it had the right to co-opt itsmembers. Further, it was believed thatmembers of the Bureau could "forget" aboutthe oath of allegiance, although formally,unlike the Academicians, they were obligedto take it. The Bureau des Longitudes washttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 8 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMan organization founded in 1795 to solve theproblem of determining position on sea –mainly the longitudinal coordinate, sincelatitude is easily determined from theposition of the sun. Since it was thought thatposition on sea was best determined byastronomical observations, the Bureau haddeveloped into an organization resemblingan academy of astronomical sciences.In November 1839 Cauchy was elected toCauchy prior to 1857the Bureau, and discovered immediately thatthe matter of the oath was not so easilydispensed with. Without his oath, the king refused to approve hiselection. For four years Cauchy was in the absurd position of beingelected, but not being approved; hence, he was not a formal memberof the Bureau, did not receive payment, could not participate inmeetings, and could not submit papers. Still Cauchy refused to takeany oaths; however, he did feel loyal enough to direct his research tocelestial mechanics. In 1840, he presented a dozen papers on thistopic to the Academy. He also described and illustrated the signeddigit representation of numbers, an innovation presented in England in1727 by John Colson. The confounded membership of the Bureaulasted until the end of 1843, when Cauchy was finally replaced byPoinsot.All through the nineteenth century the French educational systemstruggled with the question of separation of Church and State. TheCatholic Church sought freedom of education; the Church found inCauchy a staunch and illustrious ally in this struggle. He lent hisprestige and knowledge to the École Normale Écclésiastique, a schoolin Paris run by Jesuits, for training teachers for their colleges. He alsohttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 9 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMtook part in the founding of the Institut Catholique. The purpose of thisinstitute was to counter the effects of the absence of Catholicuniversity education in France. These activities did not make Cauchypopular with his colleagues who, on the whole, supported theEnlightenment ideals of the French Revolution. When a chair ofmathematics became vacant at the Collège de France in 1843,Cauchy applied for it, but got just three out of 45 votes.The year 1848 was the year of revolution all over Europe; revolutionsbroke out in numerous countries, beginning in France. King LouisPhilippe, fearful of sharing the fate of Louis XVI, fled to England. Theoath of allegiance was abolished, and the road to an academicappointment was finally clear for Cauchy. On March 1, 1849, he wasreinstated at the Faculté de Sciences, as a professor of mathematicalastronomy. After political turmoil all through 1848, France chose tobecome a Republic, under the Presidency of Louis NapoleonBonaparte, nephew of Napoleon Bonaparte, and son of Napoleon'sbrother, who had been installed as the first king of Holland. Soon(early 1852) the President became the Emperor of France, and tookthe name Napoleon III.Not unexpectedly, the idea came up in bureaucratic circles that itwould be useful to require a loyalty oath from all state functionaries,including university professors. Not always does history repeat itself,however, because this time a cabinet minister was able to convincethe Emperor to exempt Cauchy from the oath. Cauchy remained aprofessor at the University until his death at the age of 67. He receivedthe Last Rites and died at 4 a.m. on May 23, 1857.His name is one of the 72 names inscribed on the Eiffel Tower.http://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 10 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMWorkEarly workThe genius of Cauchy was illustrated in his simple solution of theproblem of Apollonius—describing a circle touching three given circles—which he discovered in 1805, his generalization of Euler's formulaon polyhedra in 1811, and in several other elegant problems. Moreimportant is his memoir on wave propagation, which obtained theGrand Prix of the French Academy of Sciences in 1816. Cauchy'swritings covered notable topics including: the theory of series, wherehe developed the notion of convergence and discovered many of thebasic formulas for q-series. In the theory of numbers and complexquantities, he was the first to define complex numbers as pairs of realnumbers. He also wrote on the theory of groups and substitutions, thetheory of functions, differential equations and determinants.Wave theory, mechanics, elasticityIn the theory of light he worked on Fresnel's wave theory and on thedispersion and polarization of light. He also contributed significantresearch in mechanics, substituting the notion of the continuity ofgeometrical displacements for the principle of the continuity of matter.He wrote on the equilibrium of rods and elastic membranes and onwaves in elastic media. He introduced[6] a 3 3 symmetric matrix ofnumbers that is now known as the Cauchy stress tensor. In elasticity,he originated the theory of stress, and his results are nearly asvaluable as those of Siméon Poisson.Number theoryhttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 11 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMOther significant contributions include being the first to prove theFermat polygonal number theorem.Complex functionsCauchy is most famous for his single-handed development of complexfunction theory. The first pivotal theorem proved by Cauchy, nowknown as Cauchy's integral theorem, was the following:where f(z) is a complex-valued function holomorphic on and within thenon-self-intersecting closed curve C (contour) lying in the complexplane. The contour integral is taken along the contour C. Therudiments of this theorem can already be found in a paper that the 24year-old Cauchy presented to the Académie des Sciences (then stillcalled "First Class of the Institute") on August 11, 1814. In full form[7]the theorem was given in 1825. The 1825 paper is seen by many asCauchy's most important contribution to mathematics.In 1826[8] Cauchy gave a formal definition of a residue of a function.This concept regards functions that have poles—isolated singularities,i.e., points where a function goes to positive or negative infinity. If thecomplex-valued function f(z) can be expanded in the neighborhood ofa singularity a aswhere φ(z) is analytic (i.e., well-behaved without singularities), then fis said to have a pole of order n in the point a. If n 1, the pole ishttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 12 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMcalled simple. The coefficient B1 is called by Cauchy the residue offunction f at a. If f is non-singular at a then the residue of f is zero at a.Clearly the residue is in the case of a simple pole equal to,where we replaced B1 by the modern notation of the residue.In 1831, while in Turin, Cauchy submitted two papers to the Academyof Sciences of Turin. In the first[9] he proposed the formula now knownas Cauchy's integral formula,where f(z) is analytic on C and within the region bounded by thecontour C and the complex number a is somewhere in this region. Thecontour integral is taken counter-clockwise. Clearly, the integrand hasa simple pole at z a. In the second paper[10] he presented theresidue theorem,where the sum is over all the n poles of f(z) on and within the contourC. These results of Cauchy's still form the core of complex functiontheory as it is taught today to physicists and electrical engineers. Forquite some time, contemporaries of Cauchy ignored his theory,believing it to be too complicated. Only in the 1840s the theory startedto get response, with Pierre-Alphonse Laurent being the firstmathematician, besides Cauchy, making a substantial contribution (hisLaurent series published in 1843).http://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 13 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMCours d'AnalyseIn addition to his work on complex functions, Cauchy was the first tostress the importance of rigor in analysis. His book Cours d'Analysehad a such an impact that Judith Grabiner writes Cauchy was "theman who taught rigorous analysis to all of Europe."(Grabiner 1981)This book is frequently noted as being the first place that inequalities,andarguments were introduced into Calculus. Cauchy exploitedinfinitesimals and wrote in his introduction that he has been ". unableto dispense with making the principalqualities of infinitely small quantitiesknown.". M. Barany claims that the Écolemandated the inclusion of infinitesimalmethods against Cauchy's better judgement(Barany 2011). Gilain argued that theThe title page of ainfinitesimal portions of the book were likelytextbook by Cauchy.a late insertion.(Gilain 1989) Laugwitz (1989)and Benis-Sinaceur (1973) argued thatCauchy was not forced to teach infinitesimals, pointing out that hecontinued to use them in his own work as late as 1853.[11][12]Cauchy gave an explicit definition of an infinitesimal in terms of asequence tending to zero. Namely, such a null sequence "becomes"an infinitesimal in Cauchy's and Lazare Carnot's terminology. Sourcesdisagree if Cauchy defined his notion of infinitesimal in terms of limits.Some have argued that such a claim is ambiguous, and essentially aplay of words on the term "limit". Similarly, some sources contest theclaim that Cauchy anticipated Weierstrassian rigor, and point outinternal contradictions in post-Weierstrassian Cauchy scholarshiprelative to Cauchy's 1853 text on the sum Louis CauchyPage 14 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMBarany[14] recently argued that Cauchy possessed a kinetic notion oflimit similar to Newton's. Regardless of how Cauchy viewed the rigorof using infinitesimal methods, these methods continued in practicelong after Cours d'Analyse both by Cauchy and other mathematiciansand can be justified by modern techniques.Taylor's theoremHe was the first to prove Taylor's theorem rigorously, establishing hiswell-known form of the remainder. He wrote a textbook[15] (see theillustration) for his students at the École Polytechnique in which hedeveloped the basic theorems of mathematical analysis as rigorouslyas possible. In this book he gave the necessary and sufficientcondition for the existence of a limit in the form that is still taught. AlsoCauchy's well-known test for absolute convergence stems from thisbook: Cauchy condensation test. In 1829 he defined for the first time acomplex function of a complex variable in another textbook.[16] In spiteof these, Cauchy's own research papers often used intuitive, notrigorous, methods;[17] thus one of his theorems was exposed to a"counter-example" by Abel, later fixed by the introduction of the notionof uniform continuity.Argument principle, stabilityIn a paper published in 1855, two years before Cauchy's death, hediscussed some theorems, one of which is similar to the "ArgumentPrinciple" in many modern textbooks on complex analysis. In moderncontrol theory textbooks, the Cauchy argument principle is quitefrequently used to derive the Nyquist stability criterion, which can beused to predict the stability of negative feedback amplifier andnegative feedback control systems. Thus Cauchy's work has a stronghttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 15 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMimpact on both pure mathematics and practical engineering.OutputCauchy was very productive, in number of papers second only toLeonhard Euler. It took almost a century to collect all his writings into27 large volumes:Oeuvres complètes d'Augustin Cauchy publiées sous la directionscientifique de l'Académie des sciences et sous les auspices deM. le ministre de l'Instruction publique (27 d OE CAUCHY 1 8)(Paris : Gauthier-Villars et fils, 1882–1974)His greatest contributions to mathematical science are enveloped inthe rigorous methods which he introduced; these are mainly embodiedin his three great treatises:Cours d'analyse de l'École royale em?id OE CAUCHY 2 3 P5 0) (1821)Le Calcul infinitésimal (1823)Leçons sur les applications de calcul infinitésimal; La géométrie(1826–1828)His other works include:Exercices d'analyse et de physique mathematique (Volume caucrich)Exercices d'analyse et de physique mathematique (Volume caucrich)Exercices d'analyse et de physique mathematique (Volume is CauchyPage 16 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMExercices d'analyse et de physique mathematique (Volume 4)(http://www.archive.org/details/117770570 004) (Paris: Bachelier,1840–1847)Analyse algèbrique (http://gallica.bnf.fr/notice?N FRBNF35030140) (Imprimerie Royale, 1821)Nouveaux exercices de mathématiques (http://gallica.bnf.fr/notice?N FRBNF37281629) (Paris : Gauthier-Villars, 1895)Courses of mechanics (for the École Polytechnique)Higher algebra (for the Faculté des Sciences)Mathematical physics (for the Collège de France).Mémoire sur l'emploi des equations symboliques dans le calculinfinitésimal et dans le calcul aux différences /f34) CR Ac ad. Sci.Paris, t. XVII, 449–458 (1843) credited as originating theoperational calculus.Politics and religious beliefsAugustin-Louis Cauchy grew up in the house of a staunch royalist.This made his father flee with the family to Arcueil during the FrenchRevolution. Their life there was apparently hard; Augustin-Louis'sfather, Louis François, spoke of living on rice, bread, and crackersduring the period. A paragraph from an undated letter from LouisFrançois to his mother in Rouen says:[18]We never had more than a half pound of bread — andsometimes not even that. This we supplement with little supplyof hard crackers and rice that we are allotted. Otherwise, weare getting along quite well, which is the important thing andgoes to show that human beings can get by with little. I shouldtell you that for my children's pap I still have a bit of fine flour,http://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 17 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMmade from wheat that I grew on my own land. I had threebushels, and I also have a few pounds of potato starch. It is aswhite as snow and very good, too, especially for very youngchildren. It, too, was grown on my own land.[19]In any event, he inherited his father's staunch royalism and hencerefused to take oaths to any government after the overthrow ofCharles X.He was an equally staunch Catholic and a member of the Society ofSaint Vincent de Paul.[20] He also had links to the Society of Jesusand defended them at the Academy when it was politically unwise todo so. His zeal for his faith may have led to his caring for CharlesHermite during his illness and leading Hermite to become a faithfulCatholic. It also inspired Cauchy to plead on behalf of the Irish duringthe Potato Famine.His royalism and religious zeal also made him contentious, whichcaused difficulties with his colleagues. He felt that he was mistreatedfor his beliefs, but his opponents felt he intentionally provoked peopleby berating them over religious matters or by defending the Jesuitsafter they had been suppressed. Niels Henrik Abel called him a"bigoted Catholic"[21] and added he was "mad and there is nothing thatcan be done about him", but at the same time praised him as amathematician. Cauchy's views were widely unpopular amongmathematicians and when Guglielmo Libri Carucci dalla Sommaja wasmade chair in mathematics before him he, and many others, felt hisviews were the cause. When Libri was accused of stealing books hewas replaced by Joseph Liouville which caused a rift between him andCauchy. Another dispute concerned Jean Marie Constant Duhameland a claim on inelastic shocks. Cauchy was later shown, by Jeanhttp://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 18 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMVictor Poncelet, to be wrong.See alsoList of topics named after Augustin-Louis CauchyCauchy–Binet formulaCauchy boundary conditionCauchy's convergence testCauchy (crater)Cauchy determinantCauchy distributionCauchy's equationCauchy–Euler equationCauchy functional equationCauchy horizonCauchy formula for repeated integrationCauchy–Frobenius lemmaCauchy–Hadamard theoremCauchy–Kovalevskaya theoremCauchy momentum equationCauchy–Peano theoremCauchy principal valueCauchy problemCauchy productCauchy's radical testCauchy–Rassias stabilityCauchy–Riemann equationsCauchy–Schwarz inequalityCauchy sequenceCauchy surfaceCauchy's theorem (geometry)Cauchy's theorem (group theory)http://en.wikipedia.org/wiki/Augustin-Louis CauchyPage 19 of 24

Augustin-Louis Cauchy - Wikipedia, the free encyclopedia1/6/14 3:35 PMMaclaurin-Cauchy testNotes1. Freudenthal 2008.2. His father's dismissal is sometimes seen as the cause of the deephatred of the French Revol

member of the Royal Swedish Academy of Sciences. In August 1833 Cauchy left Turin for Prague, to become the science tutor of the thirteen-year-old Duke of Bordeaux Henri d'Artois (1820– 1883), the exiled Crown Prince and grandson of Charles X. As a professor