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)
更新时间:2020-02-09 19:44:16
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】已知
成等差数列.又数列
中
.此数列的前
项的和
(
)对所有大于1的正整数
都有
.
(1)求数列
的第
项;
(2)若
是
的等比中项,且
为
的前
项和,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6faca16ed941f4a4b28b0662aba14ead.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c78886c192480eb5dec0ee3c61b23f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13a6e1d671215fc96e4bee3541d1096.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/dd4613271f782a90ab580131d09d03d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9517cd7186eac28accc8f3742b3c3502.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a0876215b2fd463d151523cd3c6b447.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc799cb64e5c0592e4da58de51ccf243.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/368daafa90cb0f6ce8f2bb37558cf84d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.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)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】已知数列
的通项公式为
,其中
是常数,
.
(Ⅰ)当
时,求
的值.
(Ⅱ)数列
是否可能为等差数列?证明你的结论.
(Ⅲ)若对于任意
,都有
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1fc9a3eddd037cfbc1a046f8c041706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
(Ⅰ)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/562bf10d55724c77204c6953c7fbf7e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(Ⅱ)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(Ⅲ)若对于任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9645bd4d2002993b90ec6d48f9c04f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
【推荐1】在数列
中,
,
,且
.
(1)证明:
是等差数列.
(2)求
的通项公式.
(3)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1bae03ee4ac75dacfb026290e4207dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18d8e8f821111de8075e5c3dfb22a5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3938fc9093a10b040b5ed9d18c876637.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b131b7e61b149cce2c66835b067dd0.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
(3)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e8b1fedcc25007ac7d454e44dfbc44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
【推荐2】已知数列
满足:
,且
.
(1)求
的值,并证明数列
为等差数列;
(2)令
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0489574dfdf8c3a164ea3bbef006cc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fc336b4a83bf6d66c4afcc431597f8.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c40f927a434a9cec83068b915011b0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cc1dea28318800c272430a718e28bd2.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0e7efac57331ea420c7dd1c3b6589d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次