解题方法
1 . 已知数列
和正项数列
,其中
,且满足
,数列
满足
,其中
.对于某个给定
或
的值,则下列结论中:①
;②
;③数列
单调递减;④数列
单调递增.其中正确命题的序号为___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7766f21c0004f67fbb14a1c59752a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86c0a953fe3428caca3e32f306f97f6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6be3a2848d6d4609fb56217743769149.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0b2cb1b8ee224725050200fa2b4b113.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926f8a849452fa4c90e9d13eaba10849.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a42fd21a0a3ec1314b99387eda581a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
您最近一年使用:0次
解题方法
2 . 判断正误(正确的填“正确”,错误的填“错误”)
(1)当
时,
为递增数列.( )
(2)当
时,
为常数列.( )
(3)
是等比数列,若
,则
.( )
(4)若等比数列
的公比是
,则
(
).( )
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eda6dc559d07bc22c9a0ed1e3a6d01d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfa9bf65189dfb57a61644a1cb27f361.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd9b26b74b54a192806097b698fac864.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17d2e59aeab922d37da08fd7c9f517ba.png)
(4)若等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661f8c3fabb7391571e555c2d325ab81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38b6286e5f74b604b9fb639c55d611f.png)
您最近一年使用:0次
3 . 对于数列
,存在
,使得不等式
成立,则下列说法正确的有______ .(请写出所有正确说法的序号).
①数列
为等差数列;
②数列
为等比数列;
③若
,则
;
④若
,则数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4166972dec0aa3e8694a44eeb941a08.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3508ddcc21ef2161f8cc6052e472025.png)
①数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
②数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40535f714f70909054e227e820182055.png)
④若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](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/cac691e1188206c647119a564d8b4f2b.png)
您最近一年使用:0次