444
7 Variational Principles
the most famous triumph among them was the great work the Elements. The book
was originally 13 volumes, later people supplemented 2 volumes. The most ancient
mathematical book is both extensive and profound, it is the earliest example of deductive mathematical system established by using the axiomatic method for 2000 years,
and has always been the classic textbook of geometry. British mathematician De
Morgan (Augustus, 1806.6.27–1871.3.18) once said, except the Holybible, there is
no any kind of book which has so many readers like the Elements, it is translated
into so many different languages. From 1482 to the end of the 19th century, various
versions of the Elements published more than 1000 editions in various languages.
The main works also had Data, On Divisions of Figures, Phaenomena, Catoptrics
and Optics etc.
Parseval (des Chenes, Marc Antoine, 1755.4.27–1836.8.6) French mathematician.
Born in Rosières-aux-Salines, died in Paris. Had been imprisoned for royalist in
1792, later because the published poetry is wanted against the regime napoleon, later
was wanted by Napoleon because published poetry against the regime, fled abroad. In
1796, 1799, 1802, 1813 and 1828 five times was nominated the member of the French
Academy of Sciences. Main researched the theory of differential equations, theory of
functions of real variable and functional analysis. In ordinary differential equation,
presented Parseval equality. Once submitted five papers to the French Academy of
Sciences, the date of the second paper Mémoire sur les séries et sur l’intégration
complète d’une équation aux différences partielles linéaires du second ordre, à coefficients constants was April 5, 1799, which contained the Parseval theorem about the
summation of infinite series. Gave the new statement of the theorem in July 1801.
Also using the theorem to solve some differential equations, this kind of equation is
called the Parseval equation, his method was later continuously adopted by Poisson
and others.
Fourier (Jean Baptiste Josoph, Baron, 1768.3.21–1830.5.16) French mathematician
and physicist. Born in Auxerre, Burgundy, died in Paris. Attended the Ecole Normale
Super Paris in 1794, taught at the École Polytechnique in 1795. Followed Napoleon
to go on an expedition to Egypt in 1798, served as a secretary in the army and
was appointed secretary of the Institute of Egypt. Served as a governor of the Isere
province after returning to France in 1801. Was created a baron in 1807. Was elected
a member of the French Academy of Sciences in 1817, served as permanent secretary
of the French Academy of Sciences in 1822. Became a member of the Royal Society
in 1827, Became honorary academician of the Saint Petersburg Academy of Sciences
in 1829. The main contribution was to research the theory of heat with mathematical
method. Published the book Théorie Analytique de la Chaleur in 1822, in the book
expressed the function as a series composed of trigonometric function namely Fourier
series, thus proposed any function can be expanded into a trigonometric series, which
has universal significance on mathematical physics and is widely used. The first to use
the definite integral sign, improved the proof method of law of symbol for algebraic
equation and the discriminant method of the number of real root, etc.
7 Variational Principles
the most famous triumph among them was the great work the Elements. The book
was originally 13 volumes, later people supplemented 2 volumes. The most ancient
mathematical book is both extensive and profound, it is the earliest example of deductive mathematical system established by using the axiomatic method for 2000 years,
and has always been the classic textbook of geometry. British mathematician De
Morgan (Augustus, 1806.6.27–1871.3.18) once said, except the Holybible, there is
no any kind of book which has so many readers like the Elements, it is translated
into so many different languages. From 1482 to the end of the 19th century, various
versions of the Elements published more than 1000 editions in various languages.
The main works also had Data, On Divisions of Figures, Phaenomena, Catoptrics
and Optics etc.
Parseval (des Chenes, Marc Antoine, 1755.4.27–1836.8.6) French mathematician.
Born in Rosières-aux-Salines, died in Paris. Had been imprisoned for royalist in
1792, later because the published poetry is wanted against the regime napoleon, later
was wanted by Napoleon because published poetry against the regime, fled abroad. In
1796, 1799, 1802, 1813 and 1828 five times was nominated the member of the French
Academy of Sciences. Main researched the theory of differential equations, theory of
functions of real variable and functional analysis. In ordinary differential equation,
presented Parseval equality. Once submitted five papers to the French Academy of
Sciences, the date of the second paper Mémoire sur les séries et sur l’intégration
complète d’une équation aux différences partielles linéaires du second ordre, à coefficients constants was April 5, 1799, which contained the Parseval theorem about the
summation of infinite series. Gave the new statement of the theorem in July 1801.
Also using the theorem to solve some differential equations, this kind of equation is
called the Parseval equation, his method was later continuously adopted by Poisson
and others.
Fourier (Jean Baptiste Josoph, Baron, 1768.3.21–1830.5.16) French mathematician
and physicist. Born in Auxerre, Burgundy, died in Paris. Attended the Ecole Normale
Super Paris in 1794, taught at the École Polytechnique in 1795. Followed Napoleon
to go on an expedition to Egypt in 1798, served as a secretary in the army and
was appointed secretary of the Institute of Egypt. Served as a governor of the Isere
province after returning to France in 1801. Was created a baron in 1807. Was elected
a member of the French Academy of Sciences in 1817, served as permanent secretary
of the French Academy of Sciences in 1822. Became a member of the Royal Society
in 1827, Became honorary academician of the Saint Petersburg Academy of Sciences
in 1829. The main contribution was to research the theory of heat with mathematical
method. Published the book Théorie Analytique de la Chaleur in 1822, in the book
expressed the function as a series composed of trigonometric function namely Fourier
series, thus proposed any function can be expanded into a trigonometric series, which
has universal significance on mathematical physics and is widely used. The first to use
the definite integral sign, improved the proof method of law of symbol for algebraic
equation and the discriminant method of the number of real root, etc.