名校
1 . 已知有限数列
,若满足
,n是项数,则称
满足性质
.
(1)判断数列3,2,5,1和4,3,2,5,1是否具有性质
,请说明理由;
(2)若数列
是
,公比为
的等比数列,项数为10,且具有性质
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98c5ae4ee4d5c10f5dfc7bf775270721.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(1)判断数列3,2,5,1和4,3,2,5,1是否具有性质
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
您最近一年使用:0次
2 . 已知等比数列{an}满足首项a1=2018,公比
,用
表示该数列的前n项之积,则
取到最大值时,n的值为_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/193eb979c19577a4665aad2308bbc73c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c8316409f6d7aa1a9e144eec005614e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c8316409f6d7aa1a9e144eec005614e.png)
您最近一年使用:0次