等差数列{an}与等比数列{bn}满足：a1=b1>0,a5=b5,则a3与b3的大小关系为：

正整数列{an},{bn}满足对任意正整数n,an、bn、an+1成等差数列,bn、an+1、bn+1成等比数列,证明：数列{根号bn}成等差数列 已知等比数列{bn}是公比为q与数列{an}满足bn=3^an,(1)证明数列{an}是等差数列 (2)若b8=3,且数列{an}...已知等比数列{bn}是公比为q与数列{an}满足bn=3^an,(1)证明数列{an}是等差数列 (2)若b8=3,且数列{an}的 等差数列{an}与等比数列{bn}满足：a1=b1>0,a5=b5,则a3与b3的大小关系为： 各项和为正数的数列an和bn满足an,bn,an+1成等差数列,bn,an+1,bn+1成等比数列 求证（根号bn）是等差数列 合情推理与演绎推理的题已知等差数列有一性质：若数列{an}为等差数列,数列{bn}满足bn=1/n(a1+ a2+a3……+an),则数列{bn}也是等差数列,类似上述命题,相应的等比数列有性质：若数列{an}是等比数列 设公差为非零的等差数列{An}与等比数列{Bn},满足A1=B1,A3=B3,A7=B5,求公比q 高一等比数列证明题,正数列{an}和{bn}满足,对于任意自然数n,an,bn,a(n+1)成等差数列,bn,a(n+1),b(n+1)成等比数列.证明:数列{根号bn}为等差数列 设公差不为0的等差数列{an}与递增的等比数列{bn}满足a1=b1=1,a3=b3,a7=b5,求{an}的前n项和Sn与{bn}的通项 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 已知{an},{bn}满足an=㏒abn(A>0且a不等于1),求证,若{an}是等差数列,则{bn}是等比数列 数列{an}与{bn}满足an=1/n(b1+b2+…+bn)(n∈N).求证:数列{bn}为等差数列的充要条件是数列{an}为等差数列 已知正项数列{an},{bn}满足：a1=3,a2=6,{bn}是等差数列,且对任意正整数n,都有bn,根号an,bn+1成等比数列.（1）求数列{bn}的通项公式.（2）设Sn=1/a1+1/a2+.+1/an,试比较Sn与1的大小.求哪位大仙给解下, 问道数学题.正数数列｛an}和{bn}满足：对任意自然数n,an,bn,a(n+1)成等差数列,bn.a(n+1)成等比数列.证明数列｛根号bn｝为等差数列 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. 等差数列{an}中an=2n+1,等比数列{bn}满足b1=a2,b2=a4求{bn}前n项和Sn 已知公差不为0的等差数列｛an｝满足a2=3,a1,a3,a7成等比数列 (1)求an的通项公式已知公差不为0的等差数列｛an｝满足a2=3,a1,a3,a7成等比数列(1)求an的通项公式数列{bn}满足bn=an/an+1+an+1/an,求数列bn前n 数列 (14 10:42:51)已知等比数列｛bn｝与数列｛an｝满足bn=3an,（1）判断数列｛an｝是等差还是等比数列,并证明