设数列
满足:
,
的前n项和为
.
(1)设
,求证:数列
是等比数列;
(2)求
;
(3)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/219e5b1f92cfb4890b7c2abb7ea45c9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/980d51ba3340a31964fbec9e6f243ca6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7f9677923fb404ec3f4707f392203f9.png)
更新时间:2020-06-26 13:23:26
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相似题推荐
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适中
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解题方法
【推荐1】已知抛物线
与点
,过点
作切线
(
为切点),取点
满足
;过点
作切线
(
为切点),取点
满足
;…依次得到点列
,
,…,
,数列
为单调数列.
(1)求
,
.
(2)证明:
.
(3)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52ad7c068b9b7c0fd764cf7746407079.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3169b9e651cfe7c781ab1cd05836065.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a56f2e56229a722d1f40d74d3967a3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a71fc9c0068109dad1382354570665.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c89af7170bb5cff9869993aa05c62220.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a71fc9c0068109dad1382354570665.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9e2d739c9ab27e84464962035775a81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3b9e816b14051f785aa5aae72b8eed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2857fac4963b129d99e79dcb3e13d295.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da0dc36ca4fdb257fb296cf0b9234eea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/042f6277c98e108cab95992342e4bfd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d09490514476657414d8991d633c9d6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4c5b2ecf3d4a067272790f360b5d05d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d87cc7e43a26e8bafbc6c02eb619bea9.png)
(3)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba46062609219b82c694ed3776fde0ad.png)
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【推荐2】从半径为1的半圆出发,以此向内、向外连续作半圆,且后一个半圆的直径为前一个半圆的半径,如此下去,可得到无数个半圆.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/afd70c9c-3c19-46d6-92f7-96e06cb128c2.png?resizew=180)
(1)求出所有这些半圆围城的封闭图形的周长;
(2)求出所有这些半圆围城的封闭图形的面积.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/afd70c9c-3c19-46d6-92f7-96e06cb128c2.png?resizew=180)
(1)求出所有这些半圆围城的封闭图形的周长;
(2)求出所有这些半圆围城的封闭图形的面积.
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【推荐1】已知等差数列
,
,
为其前
项的和,
,
.
(1)求数列
的通项公式;
(2)若
,求数列
的前
项的和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd5359c8fdc022d7044ffb6fdb291666.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b83d73d014a0ca4aff4282228312f55.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ea83fc1bcb18a88bd7f59f91a6ad123.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)
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【推荐2】已知等差数列
的公差为2,前
项和为
,且
成等比数列.
(Ⅰ)求数列
的通项公式;
(Ⅱ)令
,求数列
的前
项和
;
(Ⅲ)若对于
,
恒成立,求
范围.
![](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/4f8aa010f7105f3ca426c8a34880abd2.png)
(Ⅰ)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(Ⅱ)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4f2ae8b05aaba6be2d107e214c22e6d.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/fbd85b79372dc6e596d465f738c3c300.png)
(Ⅲ)若对于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cac657ea5bbf4b237a30e4074c76cc81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0068c8dfa296f54bf8c000ee15682821.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
【推荐1】已知数列
的前
项和为
,
.
(1)求证:数列
为等比数列;
(2)当
时,设
,求数列
的前
项和
.
![](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/7cbf4197111664ee3128760ba194f400.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2f2d7c81cb44416bcdf59419637682.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf83afed2af429943257c4b3bf08b087.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)
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解题方法
【推荐2】设
是数列{
}的前
项和,
,且
.
(I)求数列{
}的通项公式;
(Ⅱ)设
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7ce13e467ed5cd0081d22f5a3d80e50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ae8e0ec88d87add5a1fda629b2826ef.png)
(I)求数列{
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(Ⅱ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae5e077bdf22f0e9e69629171ebcc72a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9948001b0dcfe0aee7236787bba1f7e8.png)
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【推荐1】已知数列
的递推公式
,且首项
,求数列
的通项公式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c05c4fec4a250ce9aa564fe83daed817.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8945f021bf1969bcedd820f8ae5da1c.png)
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【推荐2】运动会期间,某班组织了一个传球游戏,甲、乙、丙三名同学参与游戏,规则如下:持球者每次将球传给另一个同学.已知,若甲持球,则他等可能的将球传给乙和丙;若乙持球,则他有
的概率传给甲;若丙持球,则他有
的概率传给甲,游戏开始时,由甲持球.记经过n次传球后甲持球的概率为
.
(1)若三次传球为一轮游戏,并且每轮游戏开始都由甲持球,规定:在一轮游戏中,若在第3次传球后,持球者是甲,为甲胜利.记随机变量X为3轮游戏后甲胜利的次数,求X的分布列和数学期望;
(2)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ffb021aa7d5a5c2f0691e337caad624.png)
(1)若三次传球为一轮游戏,并且每轮游戏开始都由甲持球,规定:在一轮游戏中,若在第3次传球后,持球者是甲,为甲胜利.记随机变量X为3轮游戏后甲胜利的次数,求X的分布列和数学期望;
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ffb021aa7d5a5c2f0691e337caad624.png)
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