设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6,则n=
来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/29 14:25:52
设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6,则n=设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6
设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6,则n=
设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6,则n=
设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6,则n=
Sn是等差数列
S6=a1*6+6(6-1)/2*d=36,则2a1+5d=12.&
最后六项的和S=an*6-6(6-1)/2*d=6an-15d
S(n-6)=Sn-S=324-(6an-15d)=144,则2an-5d=60.@
&+@:a1+an=36
Sn=(a1+an)/2*n
n=18
设Sn是等差数列{an}的前n项和好,已知S6=36,Sn=324,S(n-6)=144,n>6,则n=
设Sn为等差数列{An}的前n项和,求证:{Sn/n}是等差数列
设Sn为等差数列an的前n项和.求证Sn/n为等差数列
高一数学数列的题目(在线等答案)设等差数列{an}的前n项和为Sn,且a1=2,a3=6,设数列{1/Sn}的前n项和是Tn,求T2013的值(已求出 an=2n,Sn=n^2+n)设数列{an}的前n项和为Sn,an与Sn满足an+Sn=2,令bn=Sn+mS(n+1),
设Sn是等差数列{an}的前n项和,且S5S8,则a1
设Sn是等差数列{an}的前n项和,求证:若正整数m,n,p成等差数列,则Sm/m,Sn/n,Sp/p也成等差数列.
一道关于等差数列的题设Sn为等差数列{An}的前n项和 求证:数列{n分之Sn}是等差数列
设Sn为等差数列{an}的前n项和,已知a6+a70,那么Sn中最小的是
设Sn为等差数列{an}的前N项和,已知 a6 +a70,那么Sn 中最小的是
设Sn是等差数列an的前n项和,a5=2,an-4=30(n≥5,n∈N*),Sn=136,求n
已知数列{an}的前n项和Sn,且a1=a(a为非零常数),当n>=2时,an=2Sn^2/2已知数列{an}的前n项和Sn,且a1=a(a为非零常数),当n>=2时,an=2Sn^2/2Sn-11)求证:数列{1/Sn}是等差数列2)设bn=Sn/an,数列bn的前n项和为Tn.已
设等差数列{an}的前n项和为Sn 若a1=Sn>
等差数列{An},a1+a3+a5=105,a2+a4+a6=99,已Sn表示{An}的前n项和,使Sn达到最大值的n是?
设Sn是等差数列{an}的前n项和,已知S6=36,Sn=324,Sn-6=144(n>6),则n等于?
设数列{an}的前n项和为Sn,若对任意正整数,都有Sn=n(a1+an)/2,证明{an}是等差数列.
设Sn是等差数列{an}的前n项和,a12=-8,S9=-9,证明数列{Sn/n}是等差数列
设等差数列{an}公差d是2,前n项和为Sn,则lim(an^2-n^2)/Sn
设等差数列{an}公差d是2,前n项和为Sn,则lim(an^2-n^2)/Sn