等差数列{an},{bn}的前n项和分虽为Sn和Tn,若Sn/Tn=2n/3n+1,则a8/b8= ,an/bn=

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/29 04:09:35

等差数列{an},{bn}的前n项和分虽为Sn和Tn,若Sn/Tn=2n/3n+1,则a8/b8= ,an/bn=
等差数列{an},{bn}的前n项和分虽为Sn和Tn,若Sn/Tn=2n/3n+1,则a8/b8= ,an/bn=

等差数列{an},{bn}的前n项和分虽为Sn和Tn,若Sn/Tn=2n/3n+1,则a8/b8= ,an/bn=
等差数列,所以前n项和为an^2+bn+c的函数.Sn/Tn=2n/3n+1=2n^2/(3n^2+n),
可设sn=2n^2,Tn=3n^2+n
则an=sn-s(n-1)=2n^2-2(n-1)^2
bn=Tn-T(n-1)=3n^2+n-3(n-1)^2-n+1=3n^2+1-3(n-1)^2
a8/b8=[ 2n^2-2(n-1)^2]/[3n^2+1-3(n-1)^2]=15/23
an/bn=[ 2n^2-2(n-1)^2]/[3n^2+1-3(n-1)^2]

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},{bn}的前n项和分虽为Sn和Tn,若Sn/Tn=2n/3n+1,则a8/b8= ,an/bn= 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