抛物线焦点弦性质的推广

有资料介绍并证明了抛物线焦点弦的一个美妙性质，这就是：如果抛物线两条切线的交点在准线上，则切点弦必为焦点弦．     

抛物线焦点弦的九条性质及其应用

本文运用解析几何的核心思想——数形结合的思想从抛物线的方程和图形两个方面对抛物线焦点弦的性质做了探究,运用性质解决了一些实际问题。     

对抛物线焦点弦的一个性质的研究与推广

问题 (人民教育出版社高中<数学>第二册(上)123页第2题)过抛物线y2=2px(p＞0)的焦点F的直线与抛物线交于A,B两点,自A,B向准线作垂线,垂足分别为A',B',求证∠A'FB'=90°. 这是抛物线焦点弦的一个性质,若将其直接迁移到其它圆锥曲线上,结论显然不成立.那么能否改变它们的叙述方式再进行推广呢?下面从两个方面进行探究.     

抛物线焦点弦一性质的推广与应用

大家都知道抛物线有这样一条性质： 过抛物线y^2=2px的焦点的一条直线和此抛物线相交,设两个交点的纵坐标分别为y1,y2,则y1·y2=-p^2.     

抛物线焦点弦的性质

抛物线焦点弦的有关性质是高中数学教材中的重要内容,也是高考中的重点和热点.现以y2=2px(p＞0)为例,对其进行归纳总结,整理如下.     

抛物线焦点弦三角形的几个性质

以抛物线的顶点及其焦点弦的两个端点为顶点的三角形，叫做抛物线焦点弦三角形．抛物线焦点弦三角形中，焦点弦称为它的焦点弦边，其余两边称为它的顶点弦边．本文给出抛物线焦点弦三角形的几个性质。     

抛物线焦点弦的性质

抛物线方程及相关性质是高考命题的热点．尤其与焦点弦有关的知识更是考查直线与曲线位置关系、弦长等问题的重点．笔者以y^2=2px（p〉0）为例,总结焦点弦有关的性质．     

《抛物线焦点弦性质》教学与感悟

引导学生开展研究性学习,深入探讨抛物线的焦点弦性质,以提高学生的解题能力.     

诠释学研究中的拓展与泛化

近年来,中国诠释学研究在不断拓展的同时,出现了一种脱离诠释学本有语境的“泛化”倾向:或者把仅仅属于前诠释学形态的理解理论直接当成诠释学;或者把某些潜在的诠释学思想因素或理论萌芽放大为系统的诠释学理论;或者对“文本”作了过于宽泛的理解,使一切理解的对象都“文本化”,最终也就使任何涉及理解问题的理论都变成了“诠释学”。     

柯西不等式新推广与循环不等式校正对偶推广

给出了柯西不等式的一个新推广，并给出了循环不等式的一个校正性推广及其对偶推广。     

凸函数商的递增性在E-凸函数上的推广

凸函数具有商的递增性，E-凸函数是凸函数的推广形式．将凸函数的这种性质推广到了E-凸函数上，为讨论E-凸函数的性质奠定了基础．     

关于可拓命题与可拓推理句

研究可拓命题和可拓推理句,讨论它们的一些性质,丰富了可拓逻辑的基本要领与理论.     

求二次曲线弦中点轨迹与弦长的一种方法

介绍利用二元Taylor定理求二次曲线弦中点轨迹与弦长的一种方法.     

合理界定品牌延伸的内涵和外延

品牌延伸是一个品牌外延扩展的概念。从逻辑学来看，品牌延伸有其确定的内涵和外延，外延是由其内涵决定的．而外延的扩大又会使其内涵缩小。界定品牌延伸的内涵和外延，对于合理制定品牌延伸策略意义重大。     

Perceptual development and category generalization.

This work is concerned with developmental changes in the structure of classifications. The central claim is that young children's undifferentiated perceptions of complex stimuli are highly structured by wholistic similarity whereas older children's perceptions are structured by component dimensions. It is shown in 2 experiments that young children systematically and spontaneously generalize a category if it is well organized by overall similarity but not if it is organized by a criterial dimension. Older children, on the other hand, spontaneously apprehend and extend a category by its dimensional structure. The third experiment was designed to test the hypothesis that criterial property categories are preferred in classification tasks requiring the explicit discovery of a general rule. It was found that younger children's attention to the dimensional relations within a category increases under rule-discovery instructions, although they still have difficulty ignoring wholistic similarity relations. The trend from similarity to dimensional classification is discussed in the context of Piagetian classification tasks and family-resemblance accounts of natural categories.     

Trends of progression of student level of reasoning and generalization in numerical and figural reasoning approaches in pattern generalization

This study explored progression of students’ level of reasoning and generalization in numerical and figural reasoning approaches across grades and in different pattern generalization types. An instrument that included four figural patterns was administered to a sample of 1232 students from grades 4 to 11 from five private schools. The findings suggest that there was progressive development in the level of reasoning and generalization in each reasoning approach across clusters of grades. The level of reasoning and generalization in figural approach was higher than that for numerical approach in each grade. In addition, the level of reasoning and generalization for each approach and in each grade was not limited to one level but to several levels. The type of generalization influenced the progression of students’ level of reasoning and generalization in each approach.