About a Titan in Matrix Algebra and More.

It was in 1798, specifically on 10 March of that year, that the brilliant French mathematician Pierre Frédérich Sarrus came into this world in the French town of Saint-Affrique. Sarrus was taken to the great world of mathematics thanks to his opinions and views in favour of Bonapartist thought, since the mayor of his native Saint-Affrique refused to give him a letter of good conduct, which would lead to the impossibility of entering the Faculty of Medicine, which was one of his primary interests, having to finally opt for the study of mathematics.

And thank God for this, because Sarrus was a key player in the development of such important areas of mathematics for the advancement of mankind as the calculus of variations and the useful linear algebra.

Main Mathematical Contributions.

The Sarrus' Rule in Matrix Algebra:
Professor Pierre Sarrus succeeded in developing a very practical technique or rule for calculating determinants for 3x3 matrices (which we will describe below), which helped to facilitate and optimise many calculations in linear algebra, and further extended the theory related to matrix algebra.
The Advance of Variational Calculus:
His mathematical contributions were fundamental to the establishment and deepening of the calculus of variations, which comprises a branch of mathematical analysis that focuses on the study of the optimisation of ‘functionals’.
The Sarrus Mechanism & Articulated Parts Mechanics:
In 1853, Sarrus succeeded in solving one of the most important open problems in the mechanics of articulated parts of the time, which consisted of transforming reciprocating rectilinear movements into uniform circular movements. For this purpose, the so-called Sarrus mechanism or Sarrus Linkage was created, which is an articulated mechanical part that allows a limited circular motion to be transformed into a rectilinear motion without the need for an auxiliary guide.

The Sarrus Mechanism

GIF Source Link

Life and Performance.

Pierre Sarrus would become a Professor at very important university educational institutions of the time, most notably at the University of Strasbourg for about 30 years. In addition, in 1844 he received the prestigious 'Grand prix des sciences mathématiques', awarded for his invaluable contributions to mathematics and the teaching of mathematics.

In 1847 Professor Sarrus became a permanent member of the Academy of Sciences in Turin, Italy. He also achieved the position of Dean of the University of Strasbourg between 1839 and 1852, during which time he published a great deal of his most relevant and cited work in the Journal de mathématiques pures et appliquées de Liouville. Finally, Professor Sarrus was forced to retire from academic work in 1858 due to health problems.

Key Publications:

‘Nouvelles méthodes pour la résolution des équations'( New methods to solve equations)(1833).
His most famous mathematical contribution, at least among students, is his famous mathematical rule to calculate determinants in 3x3 order matrices, which would be introduced in the article ‘Nouvelles méthodes pour la résolution des équations’ during his years of work as a researcher at the University of Strasbourg.

Finally, we can still appreciate and benefit from the mathematical legacy that the great Professor Pierre Frédéric Sarrus left to mankind through his memorable mathematical contributions, always emphasising the importance of his work as his Sarrus' Rule for such fundamental areas for the development of mankind nowadays as can be the linear algebra and variational calculus.

Thank you, Professor Sarrus, for your unceasing dedication to the work of mathematical teaching and research.