关于反函数求导定理的注记

通过建立命题、构造反例,论述了反函数求导定理中,函数y=f(x)在点x0的某邻域连续这一条件不能减弱为f在点x0连续,即使有附加条件:f在点x0可导且导数不为零,也不足以保证结论成立     

函数可微性的几何刻画与反函数可微性的几何证明

类似于二元函数可微性的几何刻画,本文从几何的角度给出了一元函数可微的充分必要条件.利用这一等价性条件得到了反函数可微的一个更为简洁直观的几何证明.     

多元函数的可微性

给出了多元函数可微性的等价条件：利用这个条件可以简便有效地判别多元函数的可微性。     

多元函数的可微性

给出了多元函数可微性的等价条件 ;利用这个条件可以简便有效地判别多元函数的可微性     

积分第二中值定理中间点函数的连续性及可微性

主要研究按积分第二中值定理∫a^xf（t）g（t）dt=f（a）∫a^ξg（t）dt＋f（x）∫ξxg（t）dt确定的中间点ξ作为x的函数,其连续性及可微性．     

第十二届全国大学生数学竞赛预赛一道试题条件的省略

本文对第十二届全国大学生数学竞赛预赛的一道试题进行了讨论,指出题目中关于连续性的条件是可以省去的.     

关于导函数连续性的注记

就可微函数的导函数的连续性归纳出一个命题：↓Af（x）∈D（a,b）,f′（x）∈C（a,b）＜=＞f′（x）在（a,b）中不存在第二类间断点。     

关于分形插值函数的连续性和可微性

获得了由迭代函数系统(IFS)定义的两类分形插值函数具有Hlder连续性的充分条件,给出了这两类分形插值函数连续可微的充要条件,并证明了可微分形插值函数的导函数是由关联IFS生成的分形插值函数.     

积分型Cauchy中值函数若干分析性质

给出"积分型Cauchy中值函数"的定义,对"积分型Cauchy中值函数"的分析性质进行了系统讨论,证明了"积分型Cauchy中值函数"的单调性、可积性、连续性、可微性等分析性质.作为"积分型Cauchy中值函数"的特例,给出了"第一积分中值函数"的定义及"第一积分中值函数"相应的分析性质.     

关于Taylor中值函数若干分析性质的讨论

给出了"Taylor中值函数"的定义,对Taylor中值函数的分析性质进行了系统的综合讨论,证明了Taylor中值函数的单调性、可积性、连续性、可微性等分析性质.     

Differentiability of Inverse Operators and Limit Theorems for Inverse Functions

Let H be a map from a set SR ^d to R ^d . For tR ^d let _H (t) denote the distance from t to the set H(S). Consider sequences {s _n} _n1 in S such that . Any limit point of any such sequence (finite or infinite) is considered as a possible value of the inverse H ^–1(t). Any map defined in such a way will be called an SC-inverse (a selected closest inverse) to H. In the paper we study differentiability of the nonlinear operator at H=G, where G is a one-to-one map from S onto a set TR ^d with good analytic properties (specifically, a diffeomorphism). We establish compact differentiability of this operator tangentially to continuous functions and introduce a family of norms such that it is Fréchet differentiable with respect to them. We also obtain optimal bounds for the remainder of the differentiation, extending to the multivariate case recent results of Dudley. These differentiability results are applied to random maps , which could be statistical estimators of an unknown map G. For a function J on R ^d , let (J) _T be its restriction to T. It is shown that for a diffeomorphism G and for an increasing sequence of positive numbers {a _n } _n1 weak convergence of the sequence {a _n (G _n – G)} _n1 (locally in S) is equivalent to weak convergence of the sequence (locally in T) along with the convergence of the sequence to 0 in probability (locally uniformly in S). The equivalence holds for all SC-inverses and all double SC-inverses and it extends to the multivariate case a theorem of Vervaat. Moreover, each of these equivalent statements implies a kind of Taylor expansion of the SC-inverse at G (locally uniformly in T) where inv(A) denotes the inverse of a nonsingular linear transformation A in R ^d . Such limit theorems for functional inverses can be used to study asymptotic behavior of statistical estimators defined implicitly (as solutions of equations involving the empirical distribution P _n ). We show how to apply this approach to get asymptotic normality of M-estimators in the multivariate case under minimal assumptions. We consider an extension of the quantile function to the multivariate case related to M-parameters of a distribution P in R ^d (an M-quantile function)and use limit theorems for functional inverses to study limit behavior of the empirical M-quantile process. We also show how to use these theorems to study asymptotics of regression quantiles.     

Some Remarks on the Uniformizing Function in Genus 2

This article describes a practical procedure to compute, for any Fuchsian group of genus 2 acting on the unit disc, a uniformizing function for the corresponding algebraic curve.     

关于多元函数可微性的一个注记

研究了多元函数的可微性,给出了多元函数连续、可微的一些条件.     

复函数微分中值公式的注记

本文给出了复函数的一个一般性的微分中值公式,获得了该公式的“中间值”的渐近性质,给出了该性质的简洁证明.     

Some Remarks on Pseudotrees

This paper provides new results on pseudotrees. First, it is shown that pseudotrees are precisely those posets for which consistent sets, directed sets, and nonempty chains coincide. Second, we show that chain-complete pseudotrees yield complete meet-semilattices. Third, we prove that pseudotrees are precisely those posets that admit a set representation by sets of appropriate chains. This latter result generalizes results needed for applications in game theory and economics.