设数列
的前
项和为
,
且
成等差数列.
(1)证明:
为等比数列,并求数列
的通项;
(2)设
,且
,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/c9ac9d2148c312ab123686459cf18921.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cca6c5c33c184ac07e33ea1e4dae5a4f.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30b1b04112db77069cb75ad66501d564.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65aa5028388c6f81381ed321e722f81a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0169440b0b0be2db79a149e6788c29b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02e80983b88cdf6b540502816c87d13.png)
更新时间:2020-10-23 13:01:07
|
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(2)若
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您最近一年使用:0次
【推荐2】已知数列
的首项
,且满足
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84a7fd6cdba688a140e8c6f3195acf29.png)
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解答题-应用题
|
适中
(0.65)
解题方法
【推荐3】某中学以学生为主体,以学生的兴趣为导向,注重培育学生广泛的兴趣爱好,开展了丰富多彩的社团活动,其中一项社团活动为《奇妙的化学》,注重培养学生的创新精神和实践能力.本社团在选拔赛阶段,共设两轮比赛.第一轮是实验操作,第二轮是基础知识抢答赛.第一轮给每个小组提供5个实验操作的题目,小组代表从中抽取2个题目,若每个题目的实验流程操作规范可得10分,否则得0分.
(1)已知某小组会5个实验操作题目中的3个,求该小组在第一轮得20分的概率;
(2)已知恰有甲、乙、丙、丁四个小组参加化学基础知识的抢答比赛,每一次由四个小组中的一个回答问题,无论答题对错,该小组回答后由其他小组抢答下一问题,且其他小组有相同的机会抢答下一问题.记第
次回答的是甲的概率是
,若
.
①求
和
;
②写出
与
之间的关系式,并比较第9次回答的是甲和第10次回答的是甲的可能性的大小.
(1)已知某小组会5个实验操作题目中的3个,求该小组在第一轮得20分的概率;
(2)已知恰有甲、乙、丙、丁四个小组参加化学基础知识的抢答比赛,每一次由四个小组中的一个回答问题,无论答题对错,该小组回答后由其他小组抢答下一问题,且其他小组有相同的机会抢答下一问题.记第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45e03e7f8bdd53063fdccec3c99f9ac2.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/797e67927616b141ed7c6b83f8b6f4fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fee50575e3ebd56c4f46dd0bbf8e55d3.png)
②写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eb90a2118db1e9945d7b5997bf2482a.png)
您最近一年使用:0次
【推荐1】已知等差数列
的前n项和为
,
,
,
是各项均为正数的等比数列,
,且
.
(1)求
和
的通项公式;
(2)设
,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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffa01f03fb074bff35b35e07047d11b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8cd9d2c40470833cecd661528c7062b.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b284523e84ac7ed35a23411b70d7069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/385275d29d8c8a7841eaeaa3dfab2cdb.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d76d534d86b54099a07135c87e719ce4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/791fa1506890a152de30b7018673f0c2.png)
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【推荐2】已知数列
满足
,
,且数列
是等差数列.
(1)求数列
的通项公式;
(2)求数列
的前
项和
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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(1)求数列
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(2)求数列
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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