数列
,则这数列第1989项
是( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c7df25986dcbb2df5f87617f82d914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/733197b658c5488d2f5ec763d5dc3d0e.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
更新时间:2018-12-13 10:21:57
|
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单选题
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较难
(0.4)
【推荐1】数列
满足如下条件:对于
比其余99个数的和小k.已知
是互质的正整数.则
等于.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5ce374cd22f132e69b230689ef27cfc.png)
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A.50 | B.100 | C.165 | D.173 |
您最近一年使用:0次
单选题
|
较难
(0.4)
【推荐2】已知
,在
、
之间插入一个正数
,使
、
、
成等比数列;在
、
之间插入两个正数
、
,使
、
、
、
成等差数列. 则
与
的大小关系为( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8e14206c7d228a7c2259a7b27da8813.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
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A.![]() |
B.![]() |
C.![]() |
D.不确定 |
您最近一年使用:0次
单选题
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较难
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【推荐1】设递增正数列
,
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是分母为60的既约真分数.则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e705c812960b541685c6c895fc9ecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
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A.0 | B.8 | C.16 | D.30 |
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【推荐2】已知
是边长为2的正三角形,在线段
上顺次取点
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个点将
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A.![]() | B.3 | C.![]() | D.4 |
您最近一年使用:0次