Sn=2An-3n,Sn-Sn-1=An=2An-3n-2An-1+3(n-1),An=2An-1+3.
令n=1,有A1-3=0,A1=3；B1=6
（1）An=2An-1+3所以（An+3)=2(An-1+3),Bn=2Bn-1所以是等比数列
（2）由（1）,Bn通项为Bn=6*2^(n-1),所以An=6*2^(n-1)-3
设数列{An}的前n项和为Sn,且满足Sn=2An-3n,n=1,2,3……（1）设Bn=An+3,求证:数列{Bn}是
2个回答
相关问题
-
设数列{an}的前n项和为Sn，且满足Sn=2-an，n∈N+，数列{bn}满足b1=1，且bn+1=bn+an
-
3.设数列{an}的前n项和Sn=2an-4(n∈N+),数列{bn}满足:bn+1=an+2bn,且b1=2.求{bn
-
设数列an前n项和为Sn,且Sn=2^n -1 数列bn满足b1=2,b（n+1)-2bn=8an
-
设各项为正的数列{an}的前n项和为Sn，且满足：2Sn=an•（an+1）；数列{bn}满足：bn-bn-1=an-1
-
设数列{an}的前n项和为Sn且a1=1,Sn+1=4an+2(n属于正整数) （1）设bn=an/2n,求证数列{bn
-
设数列{an}的前n项和为Sn,且Sn=3an-3^（n+1)(n∈N*）.（1）令bn=an/3n-2,证明：
-
1.数列{An}的前n项和是Sn,满足Sn=(3/2)An-n/2-3/4,设Bn=log3 (An+1/2),则数列{
-
设数列{an}的前n项和为sn.已知a1=a,an+1=sn-3n,n∈N*,设bn=sn-3n,且bn≠0
-
设数列{an}的前n项和Sn=2n+1，数列{bn}满足bn=[1(n+1)log2an+n．
-
数列{an}的前n项的和Sn=2an-1（n∈N*），数列{bn}满足：b1=3，bn+1=an+bn（n∈N*）．