已知数列
,
中,
.
(1)若数列
为等比数列,且公比
,且
,
,
,求
与
的通项公式;
(2)若数列
为等差数列,其前
项和为
,且
,
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebaf2a2590bb84d646957f913d78f6dc.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f71acdb04454c77e1e25ad4f336cccfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53f5965468f4083a0be2f0547dd8ef31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5653b60d16ec4e653518f0562680250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/035937c12508091015aefe47f6c50519.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6da890f29460199ff2e7b069f03e401.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f15fac244aea2899e5a05bc330abbd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27b082cab5937fd0aecb360364b1bb41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/035937c12508091015aefe47f6c50519.png)
20-21高二·湖南长沙·阶段练习 查看更多[2]
更新时间:2021-08-23 11:39:50
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相似题推荐
解答题
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较难
(0.4)
名校
【推荐1】已知数列
满足
,
.
(1)是否能找到一个定义在
的函数
(
是常数)使得数列
是公比为3的等比数列,若存在,求出
的通项公式;若不存在,说明理由;
(2)记
,若不等式
对任意
都成立,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fc336b4a83bf6d66c4afcc431597f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e19756909ee27aad8535c6ace826e47.png)
(1)是否能找到一个定义在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/858911660b233271d57b17e358232d45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6a1a38fcf3ea3666a318794536e1233.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38335830b93ac4d99c28a8e209eecb3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77aa57b5b85adc2f9c18daf0b3c73840.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9158db048850992ae4cace688253bf4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbd4a9084dc82e6ae632cf29e793e2e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145b6046bc80d0ffecc61ac67c87ca1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
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【推荐2】已知数列
是正项等比数列,且
,
,若数列
满足
,
.
(1)求数列
和
的通项公式;
(2)已知
,记
.若
恒成立,求实数t的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94c038344552b799dc53e6bce1b245f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f732837af71ad315d4f7cb7a155eb8e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4bbb4dd887b78810c2bffdbbaae1559.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2cbcd64777f0a23fd80d8422e51b419.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b667de0002d5ebc53b9d9c804d30d44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c8bd231428639727d3c8d0d1c219b30.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
名校
【推荐1】已知数列
和
满足
若
为等比数列,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ded7ee081aeecdd892d0b353d14e9e9.png)
(1)求
和
;
(2)设
,记数列
的前
项和为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
①求
;
②求正整数 k,使得对任意
均有
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c375003a093fa3e859522c0c75a3836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ded7ee081aeecdd892d0b353d14e9e9.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb3a926dda4f15cc423a210fa5be25a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c59e7c7a84a4bdb959e95536d0404ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
②求正整数 k,使得对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2aa78c96db411c9e1e939ae16de78d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdff6afe994a994d539286067eda443d.png)
您最近一年使用:0次
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解题方法
【推荐2】已知数列
,
是
的前
项的和,且满足
,数列
是等差数列,
,
.
(1)求
,
的通项公式;
(2)设数列
的前
项和为
,设
,求
的前
项的和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdeba93dff9becc9771a7edeb6cacd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a62be876036d4104161cac7ee3f763c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0eedd7b2dfec12a6fbb5f58f240410e9.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846fa57d92d6ad44d6a0cafad1e71ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/773d0de47b6edf736429c6735ecc0b25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c59e7c7a84a4bdb959e95536d0404ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66d4e8502106802f1485c3b0f28f2664.png)
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解答题-应用题
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【推荐1】某中学在运动会期间,随机抽取了200名学生参加绳子打结计时的趣味性比赛,并对学生性别与绳子打结速度快慢的相关性进行分析,得到数据如下表:
(1)根据以上数据,能否有99%的把握认为学生性别与绳子打结速度快慢有关?
(2)现有n
根绳子,共有2n个绳头,每个绳头只打一次结,且每个结仅含两个绳头,所有绳头打结完毕视为结束.
(i)当
,记随机变量X为绳子围成的圈的个数,求X的分布列与数学期望;
(ii)求证:这n根绳子恰好能围成一个圈的概率为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f34a85a61fcc926833ed2775f376541.png)
附:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c1698cf3a31568a8ff6f6d4ee280e8.png)
性别 | 速度 | 合计 | |
快 | 慢 | ||
男生 | 65 | ||
女生 | 55 | ||
合计 | 110 | 200 |
(2)现有n
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5e07bf129b073f37b553fbca100172.png)
(i)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
(ii)求证:这n根绳子恰好能围成一个圈的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f34a85a61fcc926833ed2775f376541.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c1698cf3a31568a8ff6f6d4ee280e8.png)
0.100 | 0.050 | 0.025 | 0.010 | |
k | 2.706 | 3.841 | 5.024 | 6.635 |
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【推荐2】数列{an}是公差大于零的等差数列,a1=3,a2,a4,a7成等比;数列{bn}满足
.
(1)求数列{bn}的通项公式;
(2)记
比较cn与
(n∈N*)的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea7c3cdd565b67a92825799e6c4ab109.png)
(1)求数列{bn}的通项公式;
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/023662416c57e8524cc2aae779f4bcd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79723c05552795d638be2e4343d4af55.png)
您最近一年使用:0次