数列证明题an＞0,bn=(an+2)/an,cn=an(an+1)^2．cn为等比数列,bn＋1大于等于bn,求证：a

数列证明题an＞0,bn=(an+2)/an,cn=an(an+1)^2．cn为等比数列,bn＋1大于等于bn,求证：a 设数列{an}的前n项和为Sn=2an-4,bn=log2an,cn=1/bn^2,求证：数列{an}是等比数列? 已知数列an,bn,cn满足[a(n+1)-an][b(n+1)-bn]=cn 数学证明题: 设{an}{bn}是公比不等的两等比数列,Cn=an+bn,求证{cn}不是等比数列 已知数列an满足：a1=a2=1,an+2=an+1+an,若cn=an-4bn,bn属于整数,且cn大于等于0小于4, 数列{an}是首项为0的等差数列，数列{bn}是首项为1的等比数列，设cn=an+bn，数列{cn}的前三项依次为1，1 设{an}是等比数列,{bn}是等差数列,且b1=0,数列{cn}的前三项依次是1,1,2,且cn=an+bn 数列an中,a1=3,an=(3an-1-2)/an-1,数列bn满足bn=an-2/1-an,证明bn是等比数列 2. 数列{an}中,a1=1,Sn+1=4an+2设bn=an+1-2an,求证{bn}是等比数列,设cn=an/3n-1, 数列{an}中,a1=1,Sn+1=4an+2设bn=an+1-2an,求证{bn}是等比数列,并求其通项.设cn=an 已知数列an,bn,cn满足[a(n+1)-an][b(n+1)-bn]=cn 若数列an的通项公式为an=2n-1 设 在数列{an}中,已知a1=-1,an+a(n+1)+4n+2=0 (1)求bn=an+2n,求证：{bn}为等比数列