Pierre Frédéric Sarrus (; 10 March 1798, Saint-Affrique – 20 November 1861) was a French

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

. Sarrus was a professor at the

University of Strasbourg The University of Strasbourg (, Unistra) is a public research university located in Strasbourg, France, with over 52,000 students and 3,300 researchers. Founded in the 16th century by Johannes Sturm, it was a center of intellectual life during ...

, France (1826–1856) and a member of the

French Academy of Sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...

in Paris (1842). He is the author of several treatises, including one on the solution of numeric equations with multiple unknowns (1842); one on multiple

integrals In mathematics, an integral is the continuous analog of a sum, which is used to calculate areas, volumes, and their generalizations. Integration, the process of computing an integral, is one of the two fundamental operations of calculus,Int ...

and their integrability conditions; and one on the determination of the orbits of the

comets A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or coma surrounding the nucleus, an ...

. Sarrus discovered a

mnemonic A mnemonic device ( ), memory trick or memory device is any learning technique that aids information retention or retrieval in the human memory, often by associating the information with something that is easier to remember. It makes use of e ...

rule for solving the

determinant In mathematics, the determinant is a Scalar (mathematics), scalar-valued function (mathematics), function of the entries of a square matrix. The determinant of a matrix is commonly denoted , , or . Its value characterizes some properties of the ...

of a 3-by-3

matrix Matrix (: matrices or matrixes) or MATRIX may refer to: Science and mathematics * Matrix (mathematics), a rectangular array of numbers, symbols or expressions * Matrix (logic), part of a formula in prenex normal form * Matrix (biology), the m ...

, named Sarrus' scheme. He also demonstrated the fundamental lemma of the

calculus of variations The calculus of variations (or variational calculus) is a field of mathematical analysis that uses variations, which are small changes in Function (mathematics), functions and functional (mathematics), functionals, to find maxima and minima of f ...

. Additionally, he also developed the Sarrus linkage, the first linkage capable of transforming rotary motion into perfect straight-line motion, and vice versa. Sarrus numbers ( Fermat pseudoprimes to base 2) are also named after Sarrus, who discovered the first number (341).

References

1798 births 1861 deaths People from Saint-Affrique 19th-century French mathematicians Linear algebraists {{France-mathematician-stub