牛人速进2已知Sn是{An}前N项和 且有Sn=2An-1 则数列通项An=?
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:综合作业 时间:2024/07/02 18:43:46
牛人速进2
已知Sn是{An}前N项和 且有Sn=2An-1 则数列通项An=?
已知Sn是{An}前N项和 且有Sn=2An-1 则数列通项An=?
![牛人速进2已知Sn是{An}前N项和 且有Sn=2An-1 则数列通项An=?](/uploads/image/z/309425-41-5.jpg?t=%E7%89%9B%E4%BA%BA%E9%80%9F%E8%BF%9B2%E5%B7%B2%E7%9F%A5Sn%E6%98%AF%7BAn%7D%E5%89%8DN%E9%A1%B9%E5%92%8C+%E4%B8%94%E6%9C%89Sn%3D2An-1+%E5%88%99%E6%95%B0%E5%88%97%E9%80%9A%E9%A1%B9An%3D%3F)
A1 = S1 = 2A1 - 1
A1 = 1
An = Sn - S(n-1) = 2An-1 - 2[A(n-1))-1] = 2An -2A(n-1)
An = 2A(n-1)
An = 2^(n-1)
A1 = 1
An = Sn - S(n-1) = 2An-1 - 2[A(n-1))-1] = 2An -2A(n-1)
An = 2A(n-1)
An = 2^(n-1)
牛人速进2已知Sn是{An}前N项和 且有Sn=2An-1 则数列通项An=?
已知数列{an}a1=2前n项和为Sn 且满足Sn Sn-1=3an 求数列{an}的通项公式an
已知Sn是数列{an}的前n项和,且有Sn=n2+1,则数列{an}的通项an=______.
已知数列{an}中,a2=2,前n项和为Sn,且Sn=n(an+1)/2证明数列{an+1-an}是等差数列
已知数列{an}的前n项和为Sn,且满足Sn=2an-1,n为正整数,求数列{an}的通项公式an
已知数列{an}的前n项和为Sn,且满足Sn=2an-1(n属于正整数),求数列{an}的通项公式an
已知数列{an}前n项和为Sn,且Sn=-2an+3
数列{an}前n项和为Sn,且an+Sn=-2n-1 证明{an+2}是等比数列
已知数列{An},Sn是其前n项和,且满足3An=2Sn+n,n为正整数,求证数列{An+1/2}为等比数列
已知数列{an}的前n项和为Sn,且满足an+2Sn*Sn-1=0,a1=1/2.求证:{1/Sn}是等差数列
已知数列An中,其前n项和为Sn,A1=1,且An+1=2Sn,求An的通项公式和Sn
数列{an}前n项和为Sn,且2Sn+1=3an,求an及Sn