已知数列
满足
,
.
(Ⅰ)证明:
是等比数列;
(Ⅱ)证明:数列
中的任意三项不为等差数列;
(Ⅲ)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3cfc11343590efb61c88b627f479be9.png)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098d9e65e9676e4386c5d861c8eb03b5.png)
(Ⅱ)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(Ⅲ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b6257827fd179f2f03f23d5a9f75bc0.png)
更新时间:2018-07-04 00:25:23
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【推荐1】若数列{an}是的递增等差数列,其中的a3=5,且a1,a2,a5成等比数列,
(1)求{an}的通项公式;
(2)设bn=
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(3)是否存在自然数m,使得
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若不存在,说明理由.
(1)求{an}的通项公式;
(2)设bn=
![](https://img.xkw.com/dksih/QBM/2017/10/12/1793648458670080/1793732976902144/STEM/62e5320092b64da592270e4b50839e37.png?resizew=123)
(3)是否存在自然数m,使得
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若不存在,说明理由.
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解题方法
【推荐2】数列
的前
项和记为
且满足
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;
(1)求数列
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(2)设
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,问数列
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/c3ddd6d99ad32dd7fdb1797d8cf94786.png)
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(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63081cd919a781a9abe7828e71fc594c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eded65284816fdf6bf335b0c2a78e6a.png)
(3)设有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa8244bd8dbbfa0a28da3b065e57199a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88cc8c3ccc532e928228c31b4b6f722a.png)
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【推荐1】随着国家政策对节能环保型小排量车的调整,两款1.1升排量的
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型车的月销售量小于
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(1)求
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)比较两款车前
![](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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(3)试问从第几个月开始
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098cf97d1edb9089e365d0cd422726c8.png)
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【推荐2】某工厂2019年初有资金1000万元,资金年平均增长率可达到20%,但每年年底要扣除
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfcf777cd18a04898ababf3f055bc845.png)
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【推荐1】已知数列
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