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arXiv 0805.2674math.CO
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隐式高阶导数与孔泰和菲奥莱公式

Implicit higher derivatives, and a formula of Comtet and Fiolet

Tom Wilde

摘要:

设F(x,y)是一个二元函数,且y = f(x)在一定范围内满足F(x,y)=0.则dy/dx = -Fx/Fy,其中Fx和Fy表示F关于x和y的偏导数。很自然地,我们要寻找一个用F的偏导数表示的高阶导数d^ny/dx^n的一般表达式,1974年L. Comtet和M.菲奥莱然而,他们的公式包含一些错误。本文给出了一个修正的表达式。我们用拉格朗日反演法给出了一个推导过程,并用归纳法作了一个初等的归纳证明。我们进一步纠正孔泰和Fiolet的表达式中的一个小错误,在他们的公式中的条款的数量。

英文摘要:

Let F(x,y) be a function of two variables, and suppose y = f(x) satisfies F(x,y)=0 in some range. Then dy/dx = -Fx/Fy, where Fx and Fy denote the partial derivatives of F with respect to x and y. It is natural to seek a general expression for the higher derivatives d^ny/dx^n, in terms of partial derivatives of F, and such an expression was given in 1974 by L. Comtet and M. Fiolet. Their formula, however, contains some errors. In this note, we give a corrected expression. We give a derivation using Lagrange inversion and also an elementary proof by induction. We further correct a minor error in Comtet and Fiolet's expression for the number of terms in their formula.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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