Pierre Frédéric Sarrus
Encyclopedia
Pierre Frédéric Sarrus was a French
mathematician
.
Sarrus was professor at the University of Strasbourg
, France (1826-1856) and member of the French Academy of Sciences
in Paris (1842).
He is author of several treatises, including one on the solution of numeric equations with multiple unknowns (1842); one on multiple integrals and their integrability conditions; one on the determination of the orbits of the comets. He also discovered a mnemonic
rule for solving the determinant
of a 3-by-3 matrix
, named Sarrus' scheme
, which provides an easy-to-remember method of working out the determinant of a 3-by-3 matrix (as illustrated in "cross product
"). Sarrus also demonstrated the fundamental lemma
of the calculus of variations
.
Sarrus numbers are pseudoprime
s to base 2.
Sarrus also developed the Sarrus linkage
, the first linkage capable of transforming rotary motion into perfect straight-line motion, and vice versa.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
.
Sarrus was professor at the University of Strasbourg
University of Strasbourg
The University of Strasbourg in Strasbourg, Alsace, France, is the largest university in France, with about 43,000 students and over 4,000 researchers....
, France (1826-1856) and member of the French Academy of Sciences
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 research...
in Paris (1842).
He is author of several treatises, including one on the solution of numeric equations with multiple unknowns (1842); one on multiple integrals and their integrability conditions; one on the determination of the orbits of the comets. He also discovered a mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...
rule for solving the determinant
Determinant
In linear algebra, the determinant is a value associated with a square matrix. It can be computed from the entries of the matrix by a specific arithmetic expression, while other ways to determine its value exist as well...
of a 3-by-3 matrix
Matrix (mathematics)
In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...
, named Sarrus' scheme
Rule of Sarrus
Sarrus' rule or Sarrus' scheme is a method and a memorization scheme to compute the determinant of a 3×3 matrix. It is named after the French mathematician Pierre Frédéric Sarrus....
, which provides an easy-to-remember method of working out the determinant of a 3-by-3 matrix (as illustrated in "cross product
Cross product
In mathematics, the cross product, vector product, or Gibbs vector product is a binary operation on two vectors in three-dimensional space. It results in a vector which is perpendicular to both of the vectors being multiplied and normal to the plane containing them...
"). Sarrus also demonstrated the fundamental lemma
Lemma (mathematics)
In mathematics, a lemma is a proven proposition which is used as a stepping stone to a larger result rather than as a statement in-and-of itself...
of the calculus of variations
Calculus of variations
Calculus of variations is a field of mathematics that deals with extremizing functionals, as opposed to ordinary calculus which deals with functions. A functional is usually a mapping from a set of functions to the real numbers. Functionals are often formed as definite integrals involving unknown...
.
Sarrus numbers are pseudoprime
Pseudoprime
In number theory, the Fermat pseudoprimes make up the most important class of pseudoprimes that come from Fermat's little theorem.- Definition :...
s to base 2.
Sarrus also developed the Sarrus linkage
Sarrus linkage
The Sarrus linkage, invented in 1853 by Pierre Frédéric Sarrus, is a mechanical linkage to convert a limited circular motion to a linear motion without reference guideways. The linkage uses two perpendicular hinged rectangular plates positioned parallel over each other...
, the first linkage capable of transforming rotary motion into perfect straight-line motion, and vice versa.