某人抛掷一枚硬*,出现正反的概率都是,构造数列{an},使得an=记Sn=a1+a2+…+an(n∈N*),则...
问题详情:某人抛掷一枚硬*,出现正反的概率都是,构造数列{an},使得an=记Sn=a1+a2+…+an(n∈N*),则S4=2的概率为()A. B. C. D.【回答】C解析:依题意得知,“S4=2”表示在连续四次抛掷中恰有三次出现正面,因此“S4=2”的概率为C3·=.知...
问题详情:某人抛掷一枚硬*,出现正反的概率都是,构造数列{an},使得an=记Sn=a1+a2+…+an(n∈N*),则S4=2的概率为()A. B. C. D.【回答】C解析:依题意得知,“S4=2”表示在连续四次抛掷中恰有三次出现正面,因此“S4=2”的概率为C3·=.知...
问题详情:设数列{an}(n∈N*)是公差为d的等差数列,若a2=4,a4=6,则d= ()A.4 B.3 C.2 D.1【回答】D知识点:数列题型:选择题...
问题详情:已知数列{an}中,a1=2,且=4(an+1-an)(n∈N*),则其前9项和S9=________.【回答】1022知识点:数列题型:填空题...
问题详情:数列{an}的首项为3,{bn}为等差数列且bn=an+1-an(n∈N).若b3=-2,b10=12,则a8=________.【回答】3知识点:数列题型:填空题...
问题详情:给定*A={a1,a2,a3,…,an}(n∈N,n≥3),定义ai+aj(1≤i〈j≤n,i,j∈N)中所有不同值的个数为*A两元素和的容量,用L(A)表示.①若A={2,4,6,8},则L(A)=;②若数列{an}是等差数列,设*A={a1,a2,a3,…,am}(其中m∈N*,m为常数),则L(A)关于m的表...
BriangazedlovinglyatMaryAnn.Henry'srealnamewasMaryAnn.MaryAnnshothimaruefullook.MaryAnnwishedhewouldjustdropit.GeorgeEliotwasthepseudonymofMaryAnnEvans."Hewasalawyerbeforethat,"MaryAnnputin.Henodde...
William,31,AnnArbor,Mich.Countries,pp.180-210.AnnArbor:UniversityofMichiganPress.Soldhereexclusively,itwasengineeredattheToyotaTechnicalCenterinAnnArbor,Michigan.HenowteachesattheUniversityofMichiganL...
问题详情:已知数列T:a1,a2,…,an(n∈N*,n≥4)中的任意一项均在*{-1,0,1}中,且对"i∈N*,1≤i≤n-1,有|ai+1-ai|=1.(1)当n=4时,求数列T的个数;(2)若a1=0,且a1+a2+…+an≥0,求数列T的个数.【回答】(1)当n=4时,符合条件的数列为:0,1,0,-1; 0,1,0,1; 0,-1,0,-1;0,-1,0,1;1,0,-1,0;1,0,1,0...
问题详情:命题“nN*,f(n)N*且f(n)≤n”的否定形式是()A.nN*,f(n)N*且f(n)>n B.nN*,f(n)N*或f(n)>nC.n0N*,f(n0)N*且f(n0)>n0 D.n0N*,f(n0)N*或f(n0)>n0【回答】D知识点:常用逻辑用语题型:选择题...
问题详情:已知数列{an}的前n项和为Sn,a1=-且Sn++2=an(n≥2),计算S1,S2,S3,S4,并猜想Sn的表达式.【回答】[解]先化简递推关系:n≥2时,an=Sn-Sn-1,∴Sn++2=Sn-Sn-1,∴+Sn-1+2=0. 当n=1时,S1=a1=-.当n=2时,=-2-S1=-,∴S2=-.当n=3时,=-2-S2=-,∴S3=-.当n=4时,=-2-S3=-,∴S4=-.猜想:Sn=-,n∈N*....
问题详情:完形真空Ann:Hey,Rose!Let’s 1 amovie.Rose:Hm,Idon’tknow…Ann:Well…Let’sgotoseeTheEdge.It’s 2 thriller.Rose:Un,well,I 3 likethrillers.Idon’twanttogo,but 4 .Ann:e’sJames? ...
1、ANNbasedmusicchordperception2、ThesisconstructsANNmodelstosimulatelandusechangesbytrialanderroroncomparingthemethodsofconstructedANN.3、RESULTS:ANNhaspotentialadvantageovertraditionalmethods,soexte...
问题详情:完形填空Ann:Hey,Rose!Let’s 1 amovie.Rose:Hm,Idon’tknow…Ann:Well…Let’sgotoseeTheEdge.It’s 2 thriller.Rose:Un,well,I3 likethrillers.Idon’twanttogo,but 4 .Ann:e’sJames? 5 ...
问题详情:已知点An(n,an)为函数y=图象上的点,Bn(n,bn)的函数y=x图象上的点,其中n∈N*,设cn=an-bn,则cn与cn+1的大小关系为________.【回答】cn+1<cn知识点:不等式题型:填空题...
问题详情: 已知a1=1,an=n(an+1-an)(n∈N*),则数列{an}的通项公式是________.【回答】an=n知识点:数列题型:填空题...
问题详情:Ann____herhaireveryweek.A.isgoingtowashB.washC.washesD.iswashing【回答】C知识点:动词时态题型:选择题...
问题详情:假定你是学生会主席李华。你校将举办一场校园文化艺术表演,想邀请你校外籍教师Ann先生前来观看并作评论。请你按照下面的内容用英语给他写一封电子邮件。主题:Culture,ArtandOurCampus时间:5月31日上午8:30—11:...
1、WewerehostedbymylongtimefriendGovernorAnnRichards,whowasalsoabigsupporterofNAFTA.2、Fromwoodentowinningduringthecampaign,whenitwashardlyacertaintythathewouldbeattheincumbentAnnRichards,hehadfouriss...
1、AnnMarie,'ThatGirl'.2、Thomas'AnnMariewasatrue'60trendsetter,takingNewYorkbystormwithastylish'do,aclosetfullofmodalamodeanddon'tforgetthoseeyelashes!...
问题详情: —Ann,_____yousaythiswordinChina? —Yes.Itisveryeasy. A.may B.can C.must D.need 【回答】B知识点:情态动词题型:选择题...
问题详情:已知点An(n,an)为函数y=的图象上的点,Bn(n,bn)为函数y=x图象上的点,其中n∈N*,设cn=an-bn,则cn与cn+1的大小关系为__________.【回答】cn>cn+1知识点:推理与*题型:填空题...
问题详情:Ann,amotherof3children,isawarm-heartedsocialworkerandshehasdonealottohelppeople 56 Thefamily’sdinnerconversationoftenturnstolocalpoorfamilies,andshe 57 triesherbesttoseek(...
问题详情:1.Annhasbeenherefortwoyears.(改为一般疑问句)Annherefortwoyears?2.Wangwang,alovelydog,diedaweekago.(改为同义句)Wangwang,alovelydog,foroneweek.3.BillhasbeeninChinafortwoweeks.(对画线部分提问)has...
Representativecostonaverage25,000perheadperannum.Priceincreasehasaveraged10%perannumTherentis$2,500perannum.Therentbe$2,500perannum.Priceincreasehaveaverage10%perannum....
问题详情:已知Sn为正项数列{an}的前n项和,且满足Sn=a+an(n∈N*).(1)求a1,a2,a3,a4的值;(2)求数列{an}的通项公式.【回答】解:(1)由Sn=a+an(n∈N*),可得a1=a+a1,解得a1=1;S2=a1+a2=a+a2,解得a2=2;同理a3=3,a4=4.(2)Sn=a+an, ...