12]
63
12.
ON THE THEORY OF DETERMINANTS.
[From the Transactions of the Cambridge Philosophical Society, vol. vin. (1843), pp. 1 16.]
The following Memoir is composed of two separate investigations, each of them
having a general reference to the Theory of Determinants, but otherwise perfectly
unconnected. The name of “ Determinants ” or “ Resultants ” has been given, as is well
known, to the functions which equated to zero express the result of the elimination
of any number of variables from as many linear equations, without constant terms.
But the same functions occur in the resolution of a system of linear equations, in the
general problem of elimination between algebraic equations, and particular cases of them
in algebraic geometry, in the theory of numbers, and, in short, in almost every part
of mathematics. They have accordingly been a subject of very considerable attention
with analysts. Occurring, apparently for the first time, in Cramer’s Introduction à
VAnalyse des Lignes Courbes, 1750 : they are afterwards met with in a Memoir On
Elimination, by Bezout, Mémoires de VAcadémie, 1764; in two Memoirs by Laplace
and Vandermonde in the same collection, 1774; in Bezout’s Théorie générale des
Equations algébriques [1779] ; in Memoirs by Binet, Journal de l’Ecole Polytechnique,
vol. ix. [1813]; by Cauchy, ditto, vol. x. [1815]; by Jacobi, Crelle’s Journal, vol. xxii.
[1841] ; Lebesgue, Liouville, [vol. II. 1837], &c. The Memoirs of Cauchy and Jacobi
contain the greatest part of their known properties, and may be considered as constituting
the general theory of the' subject. In the first part of the present paper, I consider
the properties of certain derivational functions of a quantity U, linear in two separate
sets of variables (by the term “ Derivational Function,” I would propose to denote
those functions, the nature of which depends upon the form of the quantity to which
they refer, with respect to the variables entering into it, e.g. the differential coefficient
of any quantity is a derivational function. The theory of derivational functions is
apparently one that would admit of interesting developments). The particular functions
of this class which are here considered, are closely connected with the theory of the
reciprocal polars of surfaces of the second order, which latter is indeed a particular case
of the theory of these functions.
In the second part, I consider the notation and properties of certain functions
resolvable into a series of determinants, but the nature of which can hardly be explained
independently of the notation.