共查询到20条相似文献,搜索用时 421 毫秒
1.
一元二次方程的根的判别式是初中代数的重要内容之一 ,它在中学数学中有着广泛的应用 ,成为近几年全国各地中考的热点问题 .为了帮助读者更好地掌握好这部分知识内容 ,现对它在初中数学中的应用进行归纳 ,以餮读者 .应用一 :判断一元二次方程 (或二元二次方程组 )的根的情况 ;或已知根的情况 ,求方程 (或组 )中的待定系数的取值范围 .一元二次方程ax2 +bx +c =0 (a≠ 0 )的根的判别式为△ =b2 - 4ac,它与这个方程的根有着十分密切的关系 :( 1)△ >0 方程有两个不等的实数根 ;( 2 )△ =0 方程有两个相等的实数根 .( 3)△ <0 方程… 相似文献
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本文研究纯正的群的正则带.在给出这类半群的若干特征后,建立了纯正的群的正则带的构造定理.作为应用,同时给出了纯正的群的右拟正规带的构造定理. 相似文献
3.
图的邻域复形的同调群的不变性 总被引:1,自引:0,他引:1
彭允 《数学年刊A辑(中文版)》1990,(6)
本文研究了图的邻域复形同调群的不变性质。设G是一个简单连通图,x是G的一个顶点,以G/x表示G中剔去点v及其关联边而得到的图,给出了G和G/x的邻域复形的同阶同调群同构的充要条件。 相似文献
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张丹丹 《数学物理学报(A辑)》2014,34(3):473-486
研究R~n中一般的BBM-Burgers方程解的渐进行为.运用Green函数法和Fourier分析方法得到了在非零常状态u~*附近小扰动解的逐点估计,作为一个推论,又得到了L~p(R~n)(1≤p∞)空间解的最佳的衰减估计. 相似文献
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设 2 ≤ p<∞ ,(fn)是一个鞅 ,利用P(|fn|>λ‖T(fn)‖∞)型的概率指数界 ,其中 ,T是作用在鞅上的拟线性算子 ,本文估计了鞅的极大函数的Lp_范数的上界。本文结果改进与推广了先前由HITCZENKO [7,8,9]与作者 [1 0 ]得到的结果 相似文献
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设Γ为非空集,X为实Banach空间,本研究赋Day范数的c0(Γ,X)的光滑点,强光滑点,暴露点和强暴露点。 相似文献
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We find the extreme points and the smooth points of the unit ball of the Banach space n℘ of all real symmetric (n×n)-matrices. 相似文献
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GARCíA-PACHECO Francisco Javier 《中国科学A辑(英文版)》2009,52(9):1844-1848
Intuitively, non-smooth points might look like exposed points. However, in this paper we show that real Banach spaces having dimension greater than or equal to three can be equivalently renormed to obtain non-smooth points which are also non-exposed. 相似文献
14.
Peng Zhigang 《数学物理学报(B辑英文版)》1999,19(2):181-189
Byσthe author denotes the areal measure on the unit disk D=z: |z|<1. Let H'p={f(z): f(z) is analytic in D and 1/π∫D|f(z)|p dσ<+∞}. Let B(H'p)={f:f∈H'p and 1/π∫D|f(z)|p dσ1. This article researches the support points and extreme points of B(H'p). 相似文献
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A short note about exposed points in real banach spaces 总被引:1,自引:0,他引:1
Francisco J García-Pacheco 《数学物理学报(B辑英文版)》2008,28(4):797-800
We express the set of exposed points in terms of rotund points and non-smooth points.As long as we have Banach spaces each time"bigger",we consider sets of non-smooth points each time"smaller". 相似文献
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In this paper the following results are got 1. We prove that the order definitionwhich is given by J.F. Trawb on the iterative function is wrong. 2. A existent theorem on the repulsive point is given. 3. We give some theorems to judge a fixed point of iterative function. They all imporve the Ostrowski's theorems. 相似文献
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Let G be a graph and f:G→G be a continuous map. Denote by P(f), R(f) and Ω(f) the sets of periodic points, recurrent points and non-wandering points of f, respectively. In this paper we show that: (1) If L=(x,y) is an open arc contained in an edge of G such that {fm(x),fk(y)}⊂(x,y) for some m,k∈N, then R(f)∩(x,y)≠∅; (2) Any isolated point of P(f) is also an isolated point of Ω(f); (3) If x∈Ω(f)−Ω(fn) for some n∈N, then x is an eventually periodic point. These generalize the corresponding results in W. Huang and X. Ye (2001) [9] and J. Xiong (1983, 1986) [17] and [19] on interval maps or tree maps. 相似文献
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彭志刚 《数学物理学报(A辑)》2006,26(6):858-862
设T={f(z):f(z)在单位圆盘|z|<1上解析,f(z)=z ,an是实数, |an|≥|an 1|且|an|≤1}.该文找出了解析函数族T的极值点与支撑点. 相似文献
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Given a generic immersionf:S
1→S
2 of a circle into the sphere, we find the best possible lower estimation for the number of triple points of a generic immersionF: (M, S
1)→(B
3,S
2) extendingf, whereM is an oriented surface with boundary ∂M=S
1,B
3 is the 3-dimensional ball with boundaryS
2.
Supported by the Hungarian National Science and Research Foundation OTKA 2505
Supported by the Hungarian National Science and Research Foundation OTKA T4232
This article was processed by the author using the Springer-Verlag TEX P Jour1g macro package 1991. 相似文献
20.
Let I be an interval in the real line ℝ. Among the real polynomials that take I to I, we ask which ones do not commute with any increasing bijection of I other than identity. For this purely algebraic problem, the solution involves concepts in topological dynamics. Our main
characterizations are in terms of full orbits of critical points and periodic points. Using these, we obtain simpler criterion,
namely, that for no nontrivial subinterval K⊂I, the successive images {f
n
(K):n=0,1,2,…} form a pairwise disjoint collection. This problem is of interest in topological dynamics because it is about characterization
of polynomials with unique self-topological-conjugacy. 相似文献