Abstract
Let I be an interval contained in R, not reducing to a single point, E atopological vector space over R, and A and B two open subsets of E. Let (x, y, t) ↦ g(x, y, t) be a continuous map of A × B × I into E; to every differentiable map u of I into A whose derivative takes its values in B we associate the map t ↦ g(u(t), u’(t), t) of I into E, and denote it by \( \tilde g\)(u); so \( \tilde g\)is defined on the set D(A, B) of differentiable functions of I into B whose derivatives have their values in B. We shall say that the equation \( \tilde g\)(u) = 0 is a differential equation in u (relative to the real variable t); a solution of this equation is also called an integral of the differential equation (on the interval I); it is a differentiable map of I into A, whose derivative takes values in B, such that g(u(t), u’(t), t) = 0 for every t ∈ I. By abuse of language we shall write the differential equation \(\tilde g\)(u) = 0 in the form
on the understanding that x belongs to the set D(A, B).
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Bibliography
Jakob Bernoulli, Opera, 2 vol., Genève (Cramer-Philibert), 1744.
L. Euler, Opera Omnia: Institutiones calculi integralis, (1) t. XII, Leipzig-Berlin (Teubner), 1914.
J.-L. Lagrange, Œuvres, Paris (Gauthier-Villars), 1867–1890: a) Solution de différents problèmes de calcul intégral, t. I, p. 471;
J.-L. Lagrange, Œuvres, Paris (Gauthier-Villars), 1867–1890: b) Sur le mouvement des nœuds des orbites planétaires, t. IV, p. 111.
A.-L.Cauchy, Œuvrescomplètes,(2),t.XI,Paris(Gauthier-Villars),1913, p. 399 (= Exercices d’Analyse, Paris, 1840, t. I, p. 327).
A.-L. Cauchy, dans Leçons de calcul différentiel et de calcul intégral, rédigées principalement d’après les méthodes de M. A.-L. Cauchy, par l’abbé Moigno, t. II, Paris, 1844.
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© 2004 Springer-Verlag Berlin Heidelberg
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Theory, E., Spain, P. (2004). Differential equations. In: Elements of Mathematics Functions of a Real Variable. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-59315-4_5
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DOI: https://doi.org/10.1007/978-3-642-59315-4_5
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-63932-6
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