peicuiwei 幼苗
共回答了24个问题采纳率:87.5% 举报
1年前
回答问题
记等差数列{a n }的前n项和为S n ,已知a 2 +a 4 =6,S 4 =10.
1年前1个回答
等差数列题!记等差数列{An}的前n项和为Sn,若S1=4,S4=20,则该数列的公差d=?3Q!
1年前4个回答
记等差数列{an}的前n项和为Sn,若a1=1,S4=22 1,求公差d 2,若an=25,求n
已知等差数列{An}的前n项和记为Sn,a5=15,a10=25 1.通项An 2.若Sn=112,求n
1年前2个回答
已知等差数列an的各项都不为0已知等差数列{an}的各项都不为零,公差d>0且a4+a7=0记数列{1/an}的前n项和
已知等差数列{An}中,记Sn是它的前n项和,若S2=16,S4=24,求数列{an}的前n项和Tn
等差数列an中,公差d>0,且a5+a10=0,记数列-2/an的前n项和为Sn,则使Sn
数列 等差数列{an}前n项和记为Sn 已知a10=30 a20=50 Sn=242 则n=
记Sn为数列{An}前n项之和,则使LimSn(n→∞)存在的等差数列{An}————有几个?
等差数列{a n }的前n项和记为S n ,若a 2 +a 4 +a 15 的值是一个确定的常数,则数列{S n }中也
等差数列公差为2,前n项和Sn=Pn方+2n若bn=﹙2n-1﹚An分之2,记数列{Bn}的前N项和为Tn,求使Tn﹥1
(本小题满分16分)记公差d≠0的等差数列{a n }的前n项和为S n ,已知a 1 =2+ ,S 3 =12+ .
还有一道数列的题已知数列{an}和{bn}都是等差数列,数列{an}的前n项和记作Sn,数列{bn}的前n项和记作Tn,
若两个等差数列{an},{bn}的前n项和分别记为Pn和Qn,且Pn/Qn=(3n-5)/(2n+1),则a10/b10
等差数列{a n }中a 3 =7,a 1 +a 2 +a 3 =12,记 为{a n }的前n项和,令b n =a n
已知等差数列{An}中,记Sn是它的前n项和,若S2=16,S4=24,求数列{an}的前n项和
已知等差数列{an}的各项都不为零,公差d>0且a4+a7=0记数列{1/an}的前n项和为Sn,则使Sn>0成立的正整
设等差数列{an},{bn}的前n项和是Sn,Tn且Sn/Tn=3n-1/2n+3,求a8/b8=
等差数列{a n }的前n项和为S n ,且6S 5 -5S 3 =5,则a 4 =______.
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想象作文800字一篇想象作文,字数800字,内容不限,标题不限,只要是想象作文就行!
英语翻译¡Fuera de aquí!
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ink应该是不可数的吧,但是我在高中英语书第三册第四单元看到一个句子ink用了复数形式,
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