设数列
满足
,
,设
.
(1)求证:
是等比数列;
(2)设
的前
项和为
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10ddd2312f7d7d1a5d5c31fe2a9bc486.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/962c523e622988aa0eb0a2fee0f87749.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](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/56095d1a5dbc0886c616d13cdae7ac3f.png)
更新时间:2016-12-03 15:02:07
|
相似题推荐
解答题-问答题
|
较难
(0.4)
名校
解题方法
【推荐1】设数列
的首项
,且
,
,
.
(1)证明:
是等比数列;
(2)若
,数列
中是否存在连续三项成等差数列?若存在,写出这三项,若不存在说明理由.
(3)若
是递增数列,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f258934739ab0989ebaa00025abcdfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6449976ac45703bf448dd960f0c315c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/225194b4c3de347ddf755be14b4bce90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2889dd3096379db5dfdd51305bdbb743.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40f4e1236d7dc0366d9523d0cbb426be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
您最近一年使用:0次
【推荐2】已知数列
满足
,
,
.
(1)求
,
的值;
(2)求证:数列
是等比数列,并求
的通项公式;
(3)设
,若不等式
对于任意
都成立,求正数
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c7c0397404be61b1c7794adf77582f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
(2)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6fa2479fff1fb5d38410dc111c98f26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25e0b301645fc1ad3c67b4fc7e6b864a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d44759e9c18ccd118688eb4e0f967e4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
您最近一年使用:0次
【推荐1】已知正项数列
满足
,
.
(1)求数列
的通项公式;
(2)证明:
.
(附:
,
,当且仅当
或
时取等号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f6638fc813b8e47d555706a2081433.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fc336b4a83bf6d66c4afcc431597f8.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a766124d7e5a66cf31d330401bf3b9ce.png)
(附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65bc68f793cebdd43ba51dd9983b7b21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fee4e4ef6bc78dc8e69bf99c2807b7b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa448dc518e40c705576ecfcb95eaf7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87b351f16728b0023fd63678f8103c7.png)
您最近一年使用:0次
【推荐2】已知数列
,
,数列
的前n项和为
,问:是否存在正整数m,n,r,使得
成立?如果存在,请求出m,n,r的关系式;如果不存在,请说明理由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f48873417a7667f628e5c7052c96f416.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7bb72b3ebbca741b3eda49cd617c058.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a116cecd475e1cafad10bf4239b7ef.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
名校
【推荐3】材料一:有理数都能表示成
,(
,且
,s与t互质)的形式,进而有理数集可以表示为{
且
,s与t互质}.
材料二:我们知道.当
时,可以用一次多项式近似表达指数函数,即
;为提高精确度.可以用更高次的多项式逼近指数函数.
设
对等式两边求导,
得![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46fff2ffb69cbf301c9efca778fa2636.png)
对比各项系数,可得:
,
,
,…,
;
所以
,取
,有
,
代回原式:
.
材料三:对于公比为
的等比数列
,当
时,数列
的前n项和
.
阅读上述材料,完成以下两个问题:
(1)证明:无限循环小数3.7为有理数;
(2)用反证法证明:e为无理数(e=2.7182^为自然对数底数).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/537c64844b32a708d299ff92dc53c747.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0948ca0227d20b76a27cd1a6d65527fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823ab696d27d40920c39b8c910789380.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00957293044aadf33411d25f96a33922.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823ab696d27d40920c39b8c910789380.png)
材料二:我们知道.当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ba156ab181b28fa42e7e4596e69c4d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8f0237baa1472e643b6654cd8efe601.png)
设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/860870ed643c19574d5d8b3a01b6afca.png)
得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46fff2ffb69cbf301c9efca778fa2636.png)
对比各项系数,可得:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a819b1551fee7d49f197b6c7db77a495.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93dfb46889c0485f74277e329d8c5ec8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/233ede8e2b7ddd6807e67d974b7370ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8feaae3fe8a0a3504ce8f2daee1d0a50.png)
所以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51190247f6103b03b31a4f6f01420ddf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb45f673c56a289ea78831c9237e8d20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c7717db429760899f23de4d22702543.png)
代回原式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b4da092e325d22a89c38348dd5bae89.png)
材料三:对于公比为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6520ff48dba646ba8b7a7d7ae7ca35bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a107eb946e0fe41629c644b7628d5cba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12ecdb961754406f92fceddd4f77cfd3.png)
阅读上述材料,完成以下两个问题:
(1)证明:无限循环小数3.7为有理数;
(2)用反证法证明:e为无理数(e=2.7182^为自然对数底数).
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
名校
解题方法
【推荐1】已知数列
的前
项和为
,对任意的
,
恒成立.
(1)设
,求证:数列
为等比数列;
(2)设
,数列
的前
项和为
,求证:
.
![](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/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35cc6cbefd13e86b7875a08c71b55444.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/128d43fbfe37d2334f8666239efc7e32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f8ccadef8fe9114e1302123fa7ed9c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5608d0c8d3b5b997012cb6dc698d9f4.png)
您最近一年使用:0次
【推荐2】已知数列
的前
项和为
,且
对任意
都成立.
(Ⅰ)求
的值;
(Ⅱ)证明数列
是等比数列,并求出数列
的通项公式;
(Ⅲ)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/3fe95f40a1e521341a31cb2e91f403fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
(Ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0158862238e250d2a2598b7d4ecd148.png)
(Ⅱ)证明数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a080c94bf1ffea8d5af10f9688978fb5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(Ⅲ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd0f044dc82a12fd1c71872f2ac12d06.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
【推荐1】在数列
中,
.在等差数列
中,前
项和为
,
,
.
(1)求数列
和
的通项公式;
(2)设数列
满足
,数列
的前
项和记为
,试判断是否存在正整数
,使得
?若存在,求出
的值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caa960b83e70e40e60e53a6d4334c0fe.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/385275d29d8c8a7841eaeaa3dfab2cdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fe5fa40132bde317eb91fa3a399da23.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfb8be0cd38e3e7f24ee873621d22731.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de5fb39455abdcb71e7d35357c8569f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
名校
解题方法
【推荐2】已知数列
满足
,
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae1b41e841820f13d26db787a176511a.png)
(1)求
的所有可能取值;
(2)若数列
单调递增,求数列
的通项公式;
(3)对于给定的正整数k,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1bae03ee4ac75dacfb026290e4207dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3aee015e4fa175353a5b423421aa9c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae1b41e841820f13d26db787a176511a.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf637cca53efd4b054a5cbcdb1f15caa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf637cca53efd4b054a5cbcdb1f15caa.png)
(3)对于给定的正整数k,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c2e8d74f63a1222a11d04ced85e956f.png)
您最近一年使用:0次