设正项数列
的前n项和为
,且满足
,
.
(1)求
的通项公式;
(2)若
,数列
的前n项和为
,对任意
,
恒成立,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9b6e51986fe5d7a7265e0e93adcb4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34f6bf12a684139db53b2b156e83101f.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92cf0ae42e673d0c0b1b4561580e06db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4826887e248aee24900b18227fa430c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
更新时间:2024-03-29 12:59:24
|
相似题推荐
解答题-问答题
|
较难
(0.4)
解题方法
【推荐1】已知
是正项数列
的前n项和,且
.
(1)求数列
的通项公式;
(2)若不等式
恒成立,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78515a07797b245e751d0937e2cbb875.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c85d4b0f7c17c5869b1946cfba3277e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
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【推荐2】已知等差数列
满足
,
,
,
成等比数列;数列
满足
,
.
(1)求数列
,
的通项公式.
(2)数列
的前n项和为
,证明
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d93c1ae7b22099a5d4c1c4241e5ca18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e0414c0b6fda7fee5eb71976e09da80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd6c97d2ee3e74ba5730f1cbcc1d43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb27cc29c836ab7b82ad4a3acde8a3f5.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba57c83d526ac308d1461e80fcca9f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9928e46511e601913619a427ded84a3.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐1】已知数列
,
,其中
,
,且满足
,
,
,
.
(1)求证:数列
为等比数列;
(2)求数列
的前
项和为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6065aaa8f3f103d1bc960da8318ce35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcba622ae8d5e614f5f59982ce9b9b50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485dc132d9f58d3add8658da9e355ab2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ad43ccfa18a8c1c5549b50a24e22a38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ec12a9a60f82467bf7bf834a9a9b1f7.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d6bc7940536be77ccff51f687c128ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】在数列
中,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8467337eed9bb6d94c6c22c6d031839d.png)
(1)求证:数列
为等差数列;
(2)若数列
满足
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8467337eed9bb6d94c6c22c6d031839d.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0576765ab587a93bf03e8d8a3cdf6cfb.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42dd12e4dc081149aabab9a7bc2e0e8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6d889ab052426a02bc71aeaae626e41.png)
您最近一年使用:0次
解答题-应用题
|
较难
(0.4)
名校
解题方法
【推荐3】将保护区分为面积大小相近的多个区域,用简单随机抽样的方法抽取其中15个区域进行编号,统计抽取到每个区域的某种水源指标
和区域内该植物分布的数量
(
,2,…,15),得到数组
.已知
,
,
.
(1)求样本
(
,2…,15)的相关系数;
(2)假设该植物的寿命为随机变量X(X可取任意正整数).研究人员统计大量数据后发现:对于任意的
,寿命为
的样本在寿命超过k的样本里的数量占比与寿命为1的样本在全体样本中的数量占比相同,均等于0.1,这种现象被称为“几何分布的无记忆性”.
(ⅰ)求
(
)的表达式;
(ⅱ)推导该植物寿命期望
的值.
附:相关系数
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ea8f47d8d8d9e1832d52b1c7425450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4de122ae929b1acaff321dec137622ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c45176df950dfe48b8ca7eac08ee349.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef046c85a536174bec951a53d9f60b33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6449869d4e2736e9ded7e90c25886d64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9491bd97166334e901c53cb4dad33bf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ea175e26e0d37550bf2b697ac8bf4f.png)
(1)求样本
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef046c85a536174bec951a53d9f60b33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c45176df950dfe48b8ca7eac08ee349.png)
(2)假设该植物的寿命为随机变量X(X可取任意正整数).研究人员统计大量数据后发现:对于任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7399fcd570d1de4057f2059759d18cc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b00f4eb7f1bd2ccefbabf0c1dfa8f69.png)
(ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef133b0fd53a48310a82c18729575abd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7399fcd570d1de4057f2059759d18cc9.png)
(ⅱ)推导该植物寿命期望
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf3baba074e8aeb6f3ea117865bbd1b.png)
附:相关系数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5019f565326c6fec3a2494e5955a5bec.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
名校
解题方法
【推荐1】正项递增数列
的前
项和为
,
.
(1)求
的通项公式;
(2)若
,
,
,数列
的前
项和为
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.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/7ce2c4ced6e7ba363dff575a92368f6c.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af0dd3fb6af23def773e1b0032a4f3c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43d26feefa1f43bfacba2f9c92cd2b51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.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/2fc45926992c70e455741b55b582f6be.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
名校
解题方法
【推荐2】已知数列
的前n项和为
,
,
,
(
且
)
(1)求数列
的通项公式;
(2)令
,求数列
的前n项和
.
(3)设
,
,其中
,求
.
![](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/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9b6e51986fe5d7a7265e0e93adcb4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bd67791e11bf12e41449eed1781e2f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37a59558292ad6b3d0978bfd7484990.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e91f5915e62b151b18156b548e97ce34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3203575dca7e5d3233f8e3b5f0d22669.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed4f301232123cb7732d4dfacbd1fcab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7399fcd570d1de4057f2059759d18cc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caa104c781e026ca07a0378a37981a79.png)
您最近一年使用:0次