题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070129-10277.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070129-68183.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070129-20142.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070129-20517.gif)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-57149.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-86534.gif)
解析
∴a1,a3,a5…a2k-1…成等差数列,公差d=1
a2k-1=1+(k-1)·1=k∴an=
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-85860.gif)
即数列a2,a4,a6…成等比数列,公比q=2a2k=2·2k-1=2k∴an=
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-57149.gif)
(2)bn=
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-92048.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-42056.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070130-86534.gif)
核心考点
试题【(12分)数列{an}满足a1=1,a2=2,an+2=(1+cos2)an+sin,n=1、2、3…1)求a3、a4并求数列{an}的通项公式(2)设bn=,】;主要考察你对等差数列等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070115-63483.gif)
(Ⅱ)当
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070115-83477.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070116-59510.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070116-16565.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070116-50533.gif)
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![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070117-84690.gif)
(Ⅲ)设
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070117-70492.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070117-25508.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070116-50533.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070117-98937.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070117-44343.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070118-39253.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070118-46541.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070118-54039.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070118-84078.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070118-59603.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070119-45368.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070105-39765.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070105-53721.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070105-90160.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070106-20936.gif)
A.-2 | B.-![]() | C.![]() | D.2 |
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070055-36864.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070055-99245.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070055-69129.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070056-54132.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070056-48728.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070056-73026.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070056-33531.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070056-72869.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070055-69129.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070057-28856.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070057-99392.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070057-69361.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070057-56693.gif)
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![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070057-56693.gif)
已知某石油储备基地原储有石油
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070045-13626.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070045-83735.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070045-96640.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070045-69153.gif)
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![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070046-42075.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070046-86700.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070045-96640.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070046-70896.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070046-29606.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070047-40269.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070047-16129.gif)
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![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013070040-10701.gif)
( )
A.12 | B.8 | C.6 | D.4 |
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