# Joseph-Louis Lagrange

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```					Joseph-Louis Lagrange

Born January 25, 1736
Died April 10, 1813
A founder of calculus of variations
Tiffany Buscaglia
10
Early Life
•   Father was of good social position and wealth
•   Seventeen when he started getting into mathematics
•   Went to Turin for college
•   Father wanted him to be a lawyer
•   Oldest of eleven children
•   One of two who survived to adulthood

•   he began to study mathematics on his
own at age 16 and by age 19 was
appointed to a professorship at the
Royal Artillery School
•   Lagrange sent Euler a better solution
he had discovered for deriving the
central equation in the calculus of
variations
Education
•   Study at Royal Artillery School in
Turin

•   Also went to Berlin Academy of
Sciences

•   Founding member of what would
be come the Royal Academy of
Science of Turin
Personal Philosophy/religious beliefs

•   Was a roman catholic
•   Repeated the class and tackled it with more energy
•   Inspired by Edmund Halley
•   Threw himself into the study of mathematics when he turned nineteen
•   He had little interest in the subject at first
Contributions to mathematics

•   Creator of calculus of variations
•   produce his splendid Mécanique analytique
•   contributed between one and two hundred papers to the Academy of Turin
•   contributions to the fourth and fifth volumes, of the Miscellanea Taurinensia
in 1766–1773
Main Accomplishments

•   calculus of variations

•   solution of polynomial equations
•   power series and functions
•   defined the volume of Eluer’s equation
•   And surface area
•   noted that the double integral signs indicate that the two integrations must
be performed successively

•   Reflexions sur la Theorie Algebriques des Equations of 1770 was used for
solving algebraically polynomial equations
Examples of his works

.equation of the surface is given by z=f(x,y),
.If is positive from x=a to x=b, for b>a, then
f(b)-f(a) is positive
.formula f(x+i)=f(x)+iP, where P is a function
of x and i
.If f is integrable on [a,b] and f(x)>o for all x
in [a,b],
Works he wrote

•   paper entitled Recherches sur la nature et la propagation du son

•   produce his splendid Mécanique analytique

•   Published a scientific journal

•   The five volumes of his transactions, usually known as the Miscellanea
Taurinensia

•   considered to be a French             • First to prove that Pell’s
mathematician
•    his favorite subject was classical
equation x2 − ny2 = 1 has a
Latin                                   nontrivial solution in the
•   His work in Berlin covered many         integers for any non-square
topics: astronomy, the stability of     natural number
the solar system, mechanics, etc.     • He was of medium height and
•   First professor of Ecole                slightly formed, with pale blue
Polytechique                            eyes and a colorless
complexion.
•   Napoleon named Lagrange to the        • Baptized in the name of
Legion of Honour and Count of the       Giuseppe Lodovico Lagrangia
Empire in 1808
• was chosen to succeed Euler
as the director of the Berlin
•   Lagrange died in Paris                  Academy
• was buried with honor in the
Pantheon
Other accomplishments

•   Lastly, there are numerous papers on problems in astronomy. He loved
astronomy.

•   Three papers on the method of interpolation, 1783, 1792 and 1793: the part
of finite differences dealing therewith is now in the same stage as that in
which Lagrange left it.

•   In astronomy he is known for his calculations of the motions of planets.
Sources I used

•   I used think quest

•   Wikipedia, the free encyclopedia

•   Biographybase

•   I also used papers I had on him