若数列{an}是等比数列,a1>0,公比q≠1,已知lna1和2+ lna5的等差中项为lna2,且a1a2= e
(1)求{an}的通项公式;
(2)设bn=
(n∈N*),求数列{bn}的前n项和.
(1)求{an}的通项公式;
(2)设bn=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/151d30121ba2185ff3286a9013eabb0e.png)
11-12高三·山西太原·阶段练习 查看更多[1]
(已下线)2012届山西省太原市五中高三2月月考理科数学
更新时间:2016-12-01 16:43:02
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解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】已知数列
中,
,前
项和为
,且
.
(1)求
,
的值;
(2)证明:数列
是等差数列,并写出其通项公式;
(3)设
(
),试问是否存在正整数
,
(其中
,使得
,
,
成等比数列?若存在,求出所有满足条件的数对
;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f966272f7781790ff27e40db6b525253.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/e8b15fd3a64ad5b695a1a4b0e4225466.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
(2)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ad8131d0b2e2e796a52d12a7ab5a74b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45a5fdd752754e29482eab73760a1704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d7dd877103f225767609289fc7a25f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cf58a39b00433d2ffbf34e86ca2f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3abe178f96b431cf46aa8f394108d0d3.png)
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【推荐2】在①
②
③
这三个条件中选择一个补充在下面的问题中,并求解.
设等差数列
的公差为
(
),前
项和为
,等比数列
的公比为
.已知
,
,___________,
.
(1)请写出你的选择,并求数列
和
的通项公式;
(2)若数列
满足
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d61a111ab981437a0f71e6b063d8185.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/581e74360d31e2038bde239255bdbf69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e34fcef02fc86697958e8ed0364d6d60.png)
设等差数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7052b4fd2af16f73186c5bc8c12cd8.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/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aaee408bdec05bbdfcd4b841a331e61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73e96fafcc7b7f783d436f853449208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/751859e4f0b1cb2c94fd5cca373de9af.png)
(1)请写出你的选择,并求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c88a7ef007c78a93e33bd77c4396626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25c2a5f8ec179b72b201c3c0a670612a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c88a7ef007c78a93e33bd77c4396626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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解答题-问答题
|
适中
(0.65)
【推荐1】已知数列{an}的前n项和Sn=1+λan,其中λ≠0.
(1)证明{an}是等比数列,并求其通项公式;
(2)当λ=2时,求数列{
}的前n项和.
(1)证明{an}是等比数列,并求其通项公式;
(2)当λ=2时,求数列{
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06195c368e1ae2c2a3f5c0444c950ee0.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】设数列
的前
项和
满足
.
(1)求数列
的通项公式;
(2)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/18bb7c1d0429dbea3455011f99013350.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1f7f8b77390aaf5ac28af00288f803.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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