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1.
瞿萌 《呼伦贝尔学院学报》2011,19(3):89-91,91,92
利用Fourier级数方法研究了一些无穷级数^∞∑n-1 1/1+n^2 ^∞∑n-1(-1)^n/2n-1,^∞∑n-11/(2n-1)^2,^∞∑n-11/n^2等的求和.  相似文献   

2.
在课本上我们用数学归纳法证明了等式1^2+2^2+3^2+…+n^2=n(n+1)(2n+1)/6.然而n(n+1)(2n+1)/6是怎样得来的?1^3+2^3+…+n^3又等于多少?下面通过几种不同的思路进行考虑.记S1(n)=1+2+3+…+n,S2(n)=1^2+2^2+3^2+…+n^2,S3(n)=1^3+2^3+3^3+…+n^3.  相似文献   

3.
[问题313.1]对任意正整数n,求和 Sn=∞∑κ=0(|n+3^κ/3^κ+1|+|N+2·3^κ/^κ+1|).(本题推广自IMO10-6“试求∞∑κ=0|n+2^κ/2^κ+1|的值”。)  相似文献   

4.
关于一个加强的Hardy不等式   总被引:1,自引:0,他引:1  
证明了如下权系数ω(k)的不等式:(ω(k)=√k∞∑n=kn2 n∑j=i 1/√j≤4(1-θ/√k)(k∈N)),这里,θ=(1-1/4∞∑n=1 1/n2 m∑k=1 1/√k)=0.13788928^+是最佳值.从而建立了一个加强的Hardy不等式(P=2).  相似文献   

5.
胡彬 《考试》2010,(10):55-57
易错点一:对假设设而不用 例1用数学归纳法证明:1^2+2^2+3^+……n^2=1/6n(n+1)(2n+1)  相似文献   

6.
研究均匀分布区间[a,b]上U=ηn^*-η1^*——(1-q)a+qb-η1^*的统计规律,其中,0〈q〈1,η1,η2…,ηn为取自总体η的容量为n的简单随机子样,η1^*=min_l≤i≤n{ηi},ηn^*=max_l≤i≤n{ηi},求出它的密度函数,分布函数。  相似文献   

7.
小题大做     
题目 设α,b,m,n∈R,且α^2+b^2=5,ma+nb=5,则√m^2+n^2可的最小值为__.(2014年陕西卷) 1.柯西不等式 解法1 由柯西不等式,有(α^2+b^2)(m^2+n^2)≥(am+bn)^2,  相似文献   

8.
从f(x)=x在(-ππ)内的傅立叶级数展开式出发,导出形如∑n=1^∞ (-1)^n 1sin nx/n^2k-1及∑n=1^∞ (-1)^n 1con nx/n^2k的三角级数的和函数特点及函数的递推求法,从而解决形如∑n=1^∞ 1/n^2k、∑n=1^∞(-1)^n 1/N^2k、∑n=1^∞ 1/(2n-1)^2k-1(其中k∈N)等级数的求和问题。  相似文献   

9.
一个加强不等式的推广   总被引:1,自引:0,他引:1  
将哈代不等式的加强型改进∞∑n=1(1/nn∑k=1αk)^p<q^p∞∑n=1(1-1/38n^1/q)α^p/n成立的参数p的范围,由2≤p≤5推广到9/7≤p≤5(1/p 1/q=1).  相似文献   

10.
1.计算 (2008^2+4013)(2009^2-1)(2010^2-4019)/2007×2008×2009×2010×2011 2.已知正整数m、n、e、f满足mn=ef,证明m^2009+n^2009+e^2009+f^2009是合数.  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/  相似文献   

13.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?  相似文献   

14.
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.  相似文献   

15.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

16.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

17.
风的曲线     
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.  相似文献   

18.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.  相似文献   

19.
裴水妹 《华章》2007,(11):196
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.  相似文献   

20.
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