设数列{an}的前n项和为sn,a1=10,an+1=9sn+10.设Tn是数列(3/(lgan)(lgan+1)}的前n项和,求使Tn>1/4(m2-5m对所有n∈N都成立的最大正整数m的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/20 06:00:23
![设数列{an}的前n项和为sn,a1=10,an+1=9sn+10.设Tn是数列(3/(lgan)(lgan+1)}的前n项和,求使Tn>1/4(m2-5m对所有n∈N都成立的最大正整数m的值](/uploads/image/z/2730329-17-9.jpg?t=%E8%AE%BE%E6%95%B0%E5%88%97%7Ban%7D%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8C%E4%B8%BAsn%2Ca1%3D10%2Can%2B1%3D9sn%2B10.%E8%AE%BETn%E6%98%AF%E6%95%B0%E5%88%97%EF%BC%883%2F%EF%BC%88lgan%29%28lgan%2B1%29%7D%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8C%2C%E6%B1%82%E4%BD%BFTn%3E1%2F4%28m2-5m%E5%AF%B9%E6%89%80%E6%9C%89n%E2%88%88N%E9%83%BD%E6%88%90%E7%AB%8B%E7%9A%84%E6%9C%80%E5%A4%A7%E6%AD%A3%E6%95%B4%E6%95%B0m%E7%9A%84%E5%80%BC)
设数列{an}的前n项和为sn,a1=10,an+1=9sn+10.设Tn是数列(3/(lgan)(lgan+1)}的前n项和,求使Tn>1/4(m2-5m对所有n∈N都成立的最大正整数m的值
设数列{an}的前n项和为sn,a1=10,an+1=9sn+10.设Tn是数列(3/(lgan)(lgan+1)}的前n项和,求使Tn>1/4(m2-5m
对所有n∈N都成立的最大正整数m的值
设数列{an}的前n项和为sn,a1=10,an+1=9sn+10.设Tn是数列(3/(lgan)(lgan+1)}的前n项和,求使Tn>1/4(m2-5m对所有n∈N都成立的最大正整数m的值
a1=10
an+1=9sn+10
an=9sn-1+10
an+1-an=9an
an+1=10an
a1=10
an=10^n
bn=3/[lg(an)lg(an+1)]=3/[(n)(n+1)]=3*[1/n-1/(n+1)]
Tn=b1+...+bn=3[1-1/(n+1)]
Tn>(m^2-5m)/4
3-3/(n+1)>(m^2-5m)/4
n=1时
3/2>(m^-5m)/4
2m^2-10m<12
m^2-5m-6<0
-1
数列{an},中,a1=1/3,设Sn为数列{an}的前n项和,Sn=n(2n-1)an 求Sn
设数列an的首项a1等于1,前n项和为sn,sn+1=2n设数列an的首项a1等于1,前n项和为sn,sn+1=2n
设数列{an}的前n项和为Sn,a1=10,a(n+1)=9Sn+10
设数列An的前n项和为Sn,已知a1=1,An+1=Sn+3n+1求证数列{An+3}是等比数列
设数列【An】的前n项和为Sn,A1=10,An+1=9Sn+10.设Bn=lgAn,求证数列【Bn】为等差数列
设数列{an}的前n项和为Sn,若a1=1,Sn=2an+Sn+(n∈N+),则a6=
设数列An的前n项和为Sn,且a1=1,An+1=1/3Sn,求数列an的通项公式.
设数列an的前n项和为Sn,已知a1=1,3an+1=Sn,求数列an的通项公式
设数列an的前n项和为Sn,已知a1=1,3an+1=Sn,求数列an的通项公式
数列an的前n项和为Sn,a1=1,an+1=2Sn 设bn=log3an,求数列bn的前n项和Tn数列an的前n项和为Sn,a1=1,an+1=2Sn 设bn=log3an,求数列bn的前n项和Tn
设数列an的前n项和为Sn,且2an=Sn+2n+1 求a1 a2 a3 求证:数列{an+2}是等比数列 求数列{n*an}的前n项和Tn
设数列an的前n项和为Sn,且2an=Sn+2n+1 求a1 a2 a3 求证:数列{an+2}是等比数列 求数列{n*an}的前n项和Tn
设数列{an}的前n项和为sn,sn=a1(3^n-2)/2(n≥1),a4=54,则a1=
设数列{an}的前n项和为Sn,已知首项a1=3,且Sn+1+Sn=2an+1,试求此数列的通项公式an及前n项和Sn
设数列an的前n项和为Sn,Sn=a1(3^n-1)/2,且a4=54,则a1为?
设数列的前n项的和为sn,a1=2,根号sn-根号sn-1=根号2,求sn还要求an
设数列an的前n项和为Sn,已知a1=1,(2Sn)/n=a(n+1)-1/3n^2-n-2/3
设数列{an}的前n项和为Sn,已知a1=a,an+1=Sn+3^n,n∈N+.设bn=Sn+3n,求数列{bn}的通项公式