等差数列{an},{bn},的前n项和分别为Sn,Tn且Sn/Tn=(3n-1)/(2n+3)则a8/b8=快.
来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/16 10:44:34
等差数列{an},{bn},的前n项和分别为Sn,Tn且Sn/Tn=(3n-1)/(2n+3)则a8/b8=快.等差数列{an},{bn},的前n项和分别为Sn,Tn且Sn/Tn=(3n-1)/(2n
等差数列{an},{bn},的前n项和分别为Sn,Tn且Sn/Tn=(3n-1)/(2n+3)则a8/b8=快.
等差数列{an},{bn},的前n项和分别为Sn,Tn且Sn/Tn=(3n-1)/(2n+3)则a8/b8=
快.
等差数列{an},{bn},的前n项和分别为Sn,Tn且Sn/Tn=(3n-1)/(2n+3)则a8/b8=快.
Sn=n(a1+an)/2
Tn=n(b1+bn)/2
当n=15时
Sn=15(a1+a15)/2=15*2*a8/2=15a8
同理,Tn=15/b8
.
接下去么,把N=15带进去,然后两个比一下,答案就出来了
这题关键就在 : 等差出列中,a1+a(2n+1)=2*a(n+1)
已知两个等差数列an和bn的前n项和分别为已知两个等差数列{an}和{bn}的前n项和分别是An和Bn,且An/Bn= (7n+45)/(n+3),则使得an/bn为整数的正整.为什么an/bn=An-1/Bn-1?这步不懂~
已知两个等差数列{an}和{bn}的前n项和分别为An和Bn,
已知等差数列{An}和{Bn}的前n项和分 别为An和Bn,且An/Bn=(7n+41)/( n+3),则得An/Bn为整数的正整数n的 个数是.
等差数列{an},{bn}的前n项和分别为An,Bn,切An/Bn=2n/3n+1,求lim(n→∞)an/bn
等差数列an,bn的前n项和分别是Sn,TnSn/Tn=2n/3n+1 求an/bn
已知两个等差数列{an},{bn}的前n项和分别是Sn,Tn,若 Sn/Tn =(2n)/(3n+1),则 an/bn=______.
计算等差数列{an}{bn}的前n项和分别为An.Bn,且An/Bn=2n/(n+1)求limn→∞(an/bn)
等差数列{an},{bn}中的前n项和分别是An,Bn,且An/Bn=n/3n-2,则a5/b5=多少
{an}等差数列,an=21-2n,bn=|an|,求{bn}的前n项和Tnxx
等差数列除以等比数列 an=n bn=2^n-3 求an除以bn的前n项和
等差数列一道题{an}{bn}是等差数列前n项的和分别是Sn和Tn sn/tn =7n+2/n+3 求a5/b5
等差数列{an},{bn}的前n项和分别是An和Bn,且An/Bn=(7n+1)/4n+27,则a11/b11的值为?答案4/3…… 4n+27是分母 抱歉
等差数列{an}的前n项和为An,等差数列{bn}的前n项和为Bn若Bn/An=n/3n+1 1.求a5/b5 2 an/bn
等差数列(an,)(bn)的前n项的和分别是An和Bn,且满足An/Bn=4n+2/5n-2且a5/b5=
已知等差数列{an}和{bn},他们的前n项之和为An和Bn,若An/Bn=(5n+3)/(2n-1)A9/B9
等差数列{an}的前n项和sn=an^2+bn+c,则c=
已知{an},{bn}均为等差数列,前n项的和为An,Bn,且An/Bn=2n/(3n+1),求a10/b10的值
等差数列{an}{bn}的前n项和分别为An,Bn,An/Bn=7n+1/4n+27,a5/b5=?