导数及其应用

高考对导数考查的广度和深度在不断增加，已由解决问题的辅助工具上升为解决问题的必不可少的工具。考查侧重于利用导数来确定函数的单调性和最值；侧重于导数的综合应用．即利用导数解决与函数、数列、不等式有关的问题．     

导数及其应用

高考对导数考查的广度和深度在不断增加,已由解决问题的辅助工具上升为解决问题的必不可少的工具,考查侧重于利用导数来确定函数的单调性和最值;侧重于导数的综合应用,即利用导数解决与函数、数列、不等式有关的问题。     

例谈导数零点不可求问题的解决办法

<正>函数是高中数学的核心内容,导数是研究函数性质重要而又有力的工具.导数问题涉及高中数学较多的知识点和数学思想方法,具有较强的综合性,能较好评估学生的学习力,是每年高考必考题之一.高考题中有关导数问题的考查,往往是以压轴题的形式出现,有一定的灵活性,一般是先求出导数,然后求出导数为0的值即导数的零点,利用导数值的正负来确定原函数的单调性,从而使问题得到解决.但有时会碰到导函数是超越式,导数的零点不可     

用导数激活不等式

导数是高中数学的核心内容之一,用导数的方法研究函数,通过对函数的求导,判定函数的单调性和极值,确定连续函数的最大值与最小值.这里就用导数的思想方法探究不等式的解法谈谈自己的体会.     

导数的应用考点分析

导数是研究函数的工具,导数进入新教材之后,给函数问题注入了生机和活力,开辟了许多解题新途径,拓展了高考对函数问题的命题空间．导数作为进入高中考试范围的新内容,在考试中占的比重较大．常常运用导数确定函数的单调性,进而研究函数的最值和极值、求方程及不等式的解等．     

例谈导数的应用

导数是研究函数的有力工具,在高三学了导数后,许多问题的讨论方便很多．但是在这之前学习函数、解析几何、数列、不等式等内容时还没有导数工具,因此同学们往往习惯于用初等方法来处理相关问题．这样,学习导数时要有意识地用导数来解相关题目,用导数一统天下．     

导函数图像的一个应用

<正> 函数图像对阐述和研究函数的性质起着重要作用。本文所要介绍的是利用导函数的图像来帮助研究函数。由于导函数的图像可使函数、导数、二阶导数的几何解释能同时出现在一个图形里,因而对探导函数、导数、二阶导数三者之间组合成的关系起着直观启发作用,利     

n阶导数的求法探讨

求一个函数的任意阶导数往往是十分困难的.但对一些函数,在求高阶导数的过程中,呈现出明显的规律性,我们就可用数学归纳法来求它们的任意n阶导数.如一般高等数学中已求得的几个初等函数的n阶导数     

导数的“隐零点问题”

<正>导数题是高考的压轴题之一,本质上是用求导的方法来确定原函数的单调区间,进而解决函数的各种问题.通常的步骤是求原函数f(x)的导函数f′(x),接着令f′(x)=0解出f′(x)的零点,得到零点,单调区间就迎刃而解了.不过,有些函数的导数我们可以通过零点存在定理证明它确实有零点,但因为所求方程并非初等方程,无法算出其零点,即便继续求二次导也无济于事.我们将这种导数确实有零点却不能求出具体值的问题称为导数的"隐零点"问题.下面通过几道真题来介绍一些解决"隐零点"问题的方法.     

分段函数的导数

分段函数是用几个解析式子表示的函数,对每个解析式于,如果是可导的,可用初等函数的求导法则求出它们的导数,而对分界点处的导数是否存在,如果存在,如何计算,这些问题一般都用导发定义来解决,但用定义来导数要作极限运算,一般比较繁琐.如果函数具备一定的条件,可不必用定义去求.     

New third and fourth order nonlinear solvers for computing multiple roots

We present a new third order method for finding multiple roots of nonlinear equations based on the scheme for simple roots developed by Kou et al. [J. Kou, Y. Li, X. Wang, A family of fourth-order methods for solving non-linear equations, Appl. Math. Comput. 188 (2007) 1031-1036]. Further investigation gives rise to new third and fourth order families of methods which do not require second derivative. The fourth order family has optimal order, since it requires three evaluations per step, namely one evaluation of function and two evaluations of first derivative. The efficacy is tested on a number of relevant numerical problems. Computational results ascertain that the present methods are competitive with other similar robust methods.     

Optimal Eighth Order Iterative Methods

We develop an eighth order family of methods, consisting of three steps and three parameters, for solving nonlinear equations. Per iteration the methods require four evaluations (three function evaluations and one evaluation of the first derivative). Convergence analysis shows that the family is eighth-order convergent which is also substantiated through the numerical work. Computational results ascertain that family of methods are efficient and demonstrate equal or better performance as compared with other well known methods.     

The space-time fractional diffusion equation with Caputo derivatives

We deal with the Cauchy problem for the space-time fractional diffusion equation, which is obtained from standard diffusion equation by replacing the second-order space derivative with a Caputo (or Riemann-Liouville) derivative of order β∈(0, 2] and the first-order time derivative with Caputo derivative of order α∈(0, 1]. The fundamental solution (Green function) for the Cauchy problem is investigated with respect to its scaling and similarity properties, starting from its Fourier-Laplace representation. We derive explicit expression of the Green function. The Green function also can be interpreted as a spatial probability density function evolving in time. We further explain the similarity property by discussing the scale-invariance of the space-time fractional diffusion equation.     

Smoothing complements and randomized score functions

This paper establishes connections between two derivative estimation techniques:infinitesimal perturbation analysis (IPA) and thelikelihood ratio orscore function method. We introduce a systematic way of expanding the domain of the former to include that of the latter, and show that many likelihood ratio derivative estimators are IPA estimators obtained in a consistent manner through a special construction. Our extension of IPA is based onmultiplicative smoothing. A function with discontinuities is multiplied by asmoothing complement, a continuous function that takes the value zero at a jump of the first function. The product of these functions is continuous and provides an indirect derivative estimator after an appropriate normalization. We show that, in substantial generality, the derivative of a smoothing complement is a randomized score function: its conditional expectation is a derivative of a likelihood ratio. If no conditional expectation is applied, derivative estimates based on multiplicative smoothing have higher variance than corresponding estimates based on likelihood ratios.     

The fundamental solution of the space-time fractional advection-dispersion equation

A space-time fractional advection-dispersion equation (ADE) is a generalization of the classical ADE in which the first-order time derivative is replaced with Caputo derivative of order α ∈ (0, 1], and the second-order space derivative is replaced with a Riesz-Feller derivative of order β ∈ (0, 2]. We derive the solution of its Cauchy problem in terms of the Green functions and the representations of the Green function by applying its Fourier-Laplace transforms. The Green function also can be interpreted as a spatial probability density function (pdf) evolving in time. We do the same on another kind of space-time fractional advection-dispersion equation whose space and time derivatives both replacing with Caputo derivatives.     

An algebroid function and its derivative

In this paper, we investigate the value distribution of an algebroid function and its derivative, and obtain two inequations between Nevanlinna characteristic function of an algebroid function and that of its derivative. We extend Chuang Chitai's theorem of meromorphic functions to algebroid functions.     

A Generalization of the Weighted Hardy Inequality for One Class of Integral Operators

We consider the problem of finding necessary and sufficient conditions for validity of an estimate for a function by some differential operation containing a weight function rather than the ordinary derivative. This operation is referred to as the -weighted derivative.     

A Generalized Implicit Function Theorem

We prove a theorem generalizing the classical implicit function theorem to the case in which the derivative of the map is a surjective continuous linear operator. We do not assume that the kernel of the derivative is a complemented subspace.     

Estimating densities,quantiles, quantile densities and density quantiles

To estimate the quantile density function (the derivative of the quantile function) by kernel means, there are two alternative approaches. One is the derivative of the kernel quantile estimator, the other is essentially the reciprocal of the kernel density estimator. We give ways in which the former method has certain advantages over the latter. Various closely related smoothing issues are also discussed.     

Modèles linéaires généralisés fonctionnels avec dérivée

We consider the functional generalized linear model whose response function is a linear operator depending on an explanatory variable X belonging to a functional space. It has been studied, among others, by Cardot and Sarda [4]. In this paper, we consider the functional generalized linear model with derivative component, denoted MLGFD in the following, whose response function depends on a linear operator of X and on its derivative. We propose estimators for the unknown functional parameters and provide convergence rates.