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.     

浅谈"21世纪最风行的函数"——囧函数

数学函数上有一些函数图象很像"囧",这类函数人们生动地称为囧函数,当我们在函数的外侧加上一个正方形的时候,一个具有数学意义的"囧"就诞生了.     

在区间[a,b]上值域为[ka,kb]的函数例析

<正>函数f(x)在区间[a,b]上的值域为[ka,kb]的问题有很多,在历年的高考中时常出现,并且有时会给函数新命名,比如"和谐函数"、"成功函数"、"倍缩函数"、"好函数"等等.下面就通过对几类这样的函数的分析,进一步了解这类函数的解题方法和解题思路,希望能够起到抛砖引玉的作用.     

例谈零点设而不求法在解题中的应用

函数零点是函数的重要概念,特别地,导函数的零点在解决函数单调性、最值性、不等式证明等问题中地处"咽喉"至关重要.但有些问题,函数或导函数是超越函数,无法求出它的零点,实际上从问题目标来看也不需要求出零点,这时我们可对零点采取"设而不求"的方法进行处理,本文就此     

构造Hermite插值“基函数”的方法

给出了一种构造Hermite插值"基函数"的方法,画出了"基函数"的构造图.借助于这组"基函数"的线性组合来求Hermite插值多项式,计算过程非常简单.之后,把这种求"基函数"的方法推广到了二元Hermite插值中,为二元Hermite插值"基函数"的构造提供了一种简单实用的方法.     

第一积分中值函数

通过上下确界,给出了"第一积分中值函数"的定义,对"第一积分中值函数"的分析性质进行了系统的讨论,证明了"第一积分中值函数"的单调性、可积性、连续性、可导性等分析性质.     

例谈“零点设而不求”在解题中的应用

函数零点是函数的重要概念,特别地,导函数的零点在解决函数单调性、最值性、不等式证明等问题中地处"咽喉",至关重要.但有些问题,函数或导函数是超越函数无法求出它的零点,实际上从问题目标来看也不需要求出零点,这时我们可对零点采取"设而不求"的方法进行处理,本文就此举例说明零点设而不求法在解题中的应用.     

实现目标函数几何化的几种形式

线性规划问题是高中数学的重要内容,是"沟通"代数与几何的重要桥梁,以其直观性地解决问题而"一枝独秀".在有关的线性规划问题中,由于目标函数的形式的多样化与隐蔽性,所以我们要充分研究与挖掘目标函数的几何意义,将其由"数"向"形"转化,使目标函数具体化、明朗化,是我们解决这类问题的关键所在.本文通过几个例题罗列了实现目标函数几何化的几种常见形式.……     

抽象函数不“抽象”

<正>在高一函数教学中,经常会遇到令学生头疼的抽象函数的性质探究问题,如"函数f(x)对任意实数x,y都有f(x+y)=f(x)+f(3)成立,判断f(x)的奇偶性".高一学生以前很少接触到未知解析式的"抽象函数",他们首先会想:这是哪个函数?它的解析式是什么?学生可能会猜f(x)是初中学的正比例函数,更有学生设f(x)=kx,但"你怎么知道这个函数就是f(x)=kx?"其实这个问题本来就不容易,更何况对于高一刚接触抽象函数的学生呢!这个"抽象函数"的解涉及到高等数学.在近年的一些大学自主招生考试中频繁出现这种"抽象函     

农村初中生函数入门知识教学策略研究

数学是一门工具性学科,高度抽象性、逻辑严密性、广泛应用性是其显著的特点.初中数学是在小学数学对"数"与"形"的学习基础之上,进一步扩展、深入学习的.函数是数学的重要组成部分.从函数的定义开始,函数就带给学生一种复杂、难懂的感受,很多学生甚至认为函数是一种"卖弄"的学问,认为函数是将简单的东西复杂化,把具体的东西描述成模糊的、不明确的,把容易懂的讲成谁也听不懂的,其实这正是函数的抽象化特性带给学生的困惑.     

A Method for Converting a Class of Univariate Functions into d.c. Functions

D.c. functions are functions that can be expressed as the sum of a concave function and a convex function (or as the difference of two convex functions). In this paper, we extend the class of univariate functions that can be represented as d.c. functions. This expanded class is very broad including a large number of nonlinear and/or nonsmooth univariate functions. In addition, the procedure specifies explicitly the functional and numerical forms of the concave and convex functions that comprise the d.c. representation of the univariate functions. The procedure is illustrated using two numerical examples. Extensions of the conversion procedure for discontinuous univariate functions is also discussed.     

On Almost Strongly θ-Semi-Continuous Functions

Beceren et al. [2] introduced and investigated a new class of functions called almost strongly -semi-continuous functions. The purpose of this paper is to investigate some more properties of these functions. It is shown that these functions are weaker than strongly -semi-continuous functions and stronger than -semi-continuous functions.     

Scalar Products of Symmetric Functions and Matrix Integrals

We present relations between Hirota-type bilinear operators, scalar products on spaces of symmetric functions, and integrals defining matrix-model partition functions. Using the fermionic Fock space representation, we prove an expansion of an associated class of KP and 2-Toda tau functions _r,n in a series of Schur functions generalizing the hypergeometric series and relate it to the scalar product formulas. We show how special cases of such tau functions can be identified as formal series for partition functions. A closed form expansion of log _r,n in terms of Schur functions is derived.     

Asymptotic analysis of Θ-hypergeometric functions

We define the -hypergeometric functions as a generalization of the hypergeometric functions associated with root systems of Heckman and Opdam. In the geometric setting, the -hypergeometric functions can be specialized to Harish-Chandras spherical functions on Riemannian symmetric spaces of noncompact type, and also to the spherical functions on noncompactly causal symmetric spaces. After describing their regularity properties, we prove estimates for the -hypergeometric functions which are uniform in the space parameter and locally uniform in the spectral parameter. Particular cases are sharp uniform estimates for the Harish-Chandra series up to the walls of the positive Weyl chamber. New estimates for the spherical functions on noncompactly causal symmetric spaces are deduced. Mathematics Subject Classification (2000) 33C67, 43A90, 43A85     

On Generalized Linearity of Quadratic Fractional Functions

Quadratic fractional functions are proved to be quasilinear if and only if they are pseudo-linear. For these classes of functions, some characterizations are provided by means of the inertia of the quadratic form and the behavior of the gradient of the function itself. The study is then developed showing that generalized linear quadratic fractional functions share a particular structure. Therefore it is possible to suggest a sort of canonical form for those functions. A wider class of functions given by the sum of a quadratic fractional function and a linear one is also studied. In this case generalized linearity is characterized by means of simple conditions. Finally, it is deepened on the role played by generalized linear quadratic fractional functions in optimization problems.     

On information functions and their polars

LetP be a closed convex cone. Information functions, i.e., nonnegative functions onP which are positively homogeneous and concave, are shown to be in a one-to-one correspondence with certain convex subsets ofP. Information functions are always isotone with respect to the vector ordering induced byP, and this order-preserving property distinguishes them from their convex analogues, gauge functions. A polarity concept for information functions is proposed which slightly deviates from the well-known polarity correspondence for gauge functions. Finally, those functions are characterized which differ from information functions only by some nondecreasing concave transformation.     

Generalized Bessel Functions for p-Radial Functions

Suppose that and p > 0. In this paper we study the generalized Bessel functions for the surface , introduced by D.St.P. Richards. We derive a recurrence relation for these functions and utilize a series representation to relate them to the classical symmetric functions. These generalized Bessel functions are symmetric with respect to the action of the hyperoctahedral group W_d, which is the symmetry group of the unit sphere. By means of this symmetry under W_d, we further express these generalized Bessel functions in terms of Bessel functions for certain finite reflection groups. For the case in which p = 2, our representations lead to known relations for the classical Bessel functions of order (d - 2)/2. For the case in which p = 1, the generalized Bessel functions have been studied by Berens and Xu in the analysis of summability problems for 1-radial functions, and we show how their results may be framed within our more general context.     

Solving knapsack sharing problems with general tradeoff functions

A knapsack sharing problem is a maximin or minimax mathematical programming problem with one or more knapsack constraints (an inequality constraint with all non-negative coefficients). All knapsack sharing algorithms to date have assumed that the objective function is composed of single variable functions called tradeoff functions which are strictly increasing continuous functions. This paper develops optimality conditions and algorithms for knapsack sharing problems with any type of continuous tradeoff function including multiple-valued and staircase functions which can be increasing, decreasing, unimodal, bimodal, or even multi-modal. To do this, optimality conditions are developed for a special type of multiple-valued, nondecreasing tradeoff function called an ascending function. The optimal solution to any knapsack sharing problem can then be found by solving an equivalent problem where all the tradeoff functions have been transformed to ascending functions. Polynomial algorithms are developed for piecewise linear tradeoff functions with a fixed number of breakpoints. The techniques needed to construct efficient algorithms for any type of tradeoff function are discussed.     

On θ -Preirresolute Functions

We introduce a new class of functions called -preirresolute functions which is contained in the class of quasi preirresolute functions and contains the class of preirresolute functions. It is shown that p-closedness and -connectedness are preserved by -preirresolute surjections.