设bn=1/2*3/4*5/6*...*(2n-1)/(2n) ,求证:b1+b2+...+bn

设bn=1/2*3/4*5/6*...*(2n-1)/(2n) ,求证:(1)bn 设bn=1/2*3/4*5/6*...*(2n-1)/(2n) ,求证:b1+b2+...+bn 设数列{bn},b1=1,bn+1=lnbn+bn+2,证明bn lim(3an+4bn)=8 lim(6an-bn)=1 求lim(3an+bn) 要设3an+4bn=m 6an-bn=t第二题若an=(5-3x）^n 1)an存在极限,求x范围 2）an极限为零 求x范围 设各项均为正数的数列{an}和{bn}满足5^[an ],5^[bn] ,5^[a(n+1)] .设各项均为正数的数列{an}和{bn}满足5^[an ],5^[bn] ,5^[a(n+1)] 成等比数列,lg[bn],lg[a(n+1)],lg[bn+1]成等差数列,且a1=1,b1=2,a2=3,求通项an、bn. 设数列{bn}满足bn=n^2/2^(n+1),证明:bn 设数列{an}{bn}满足a1=b1=6 a2=b2=4 a3=b3=3若{an+1 - an}为等差数列.{bn+1 -bn}为等比数列.分别求{an}{bn}的通项公式. 设数列｛an},{bn}满足；a1=4 a2=5/2,an+1=an+bn/2,bn+1=2anbn/an+bn 用数列an表示an+1;并证明；任意n属于设数列｛an},{bn}满足；a1=4 a2=5/2,an+1=an+bn/2,bn+1=2anbn/an+bn （1）用数列an表示an+1;并证明；任意n属于N*都 已知an=5^[2^(n-1)] -3,设bn={1/（an-6）}-{1/（an²+6an）},数列bn的前n项和为Tn,求证-5/16≤Tn＜-1/4 数列{an}中,a1=1,a(n+1)=5/2-1/an.设bn=1/(an-2),求{bn}的通项公式（2）设cn=-3n*bn,求{cn}前n项和 设向量a=（x,2）,b=（x+n,2x-3/2）,函数fx=ab在[0,1]上的最小值和最大值的和为an数列bn的前n项和满足Sn+4bn=n（n∈N*）一问求an,2：证明{bn-1}为等比,并求bn bn=﹣（4/5）∧（n+1）+1对不对?3：令cn=﹣an（bn 设数列{an}和{bn}满足:a1=b1=6,a2=b2=4,a3=b3=3,数列{an+1-an}是等差数列···设数列{an}和{bn}满足:a1=b1=6,a2=b2=4,a3=b3=3,数列{an+1-an}是等差数列,Sn为数列{bn}的前n项和,且Sn=2n-bn+10,(1)分别求{an}{bn}的通项公式(2 设数列An,Bn 满足a1=b1=6,a2=b2=4,a3=b3=3设数列An,Bn 满足a1=b1=6,a2=b2=4,a3=b3=3,若{an+1 -an}是等差数列,{bn+1-bn}是等比数列.1.求An Bn 通项2.求数列AN最小项及最小值3.是否存在K属于N*,使ak-bk属于（0.0.5）若存 设各项均为正数的数列{an}和{bn}满足:an,bn,an+1成等差数列,bn,an+1,bn+1等比数列且a1=1,b1=2,a2=3求通项an,bn 设各项均为正数的数列｛an}和｛bn}满足：an,bn,an+1成等差数列,bn,an+1,bn+1成等比数列,且a1=1,b1=2,a2=3,求通项an,bn 数列设a1=2,a（n+1）=2/（an+1）,bn=|an+2/an-1|,n属于正整数,则数列{bn}的通项bn=已知数列1,1/2,2/1,1/3,2/2,3/1,1/4,2/3,3/2,4/1……则5/6是数列的第几项? 数列满足a1=1 an=2an-1-3n+6 设bn=an-3n 求证bn是等比数列 an=2n-5,bn=an/2^n,设bn的前n项和为tn,证明；1/4大于等于tn小于1