已知
,且
.
(1)求n的值;
(2)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/673e21d7c54b435fdbbb54e5eed28f07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1063d00c29494f442e765b57a228dd11.png)
(1)求n的值;
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ee51179ac83a9d9f1d30fe03d414013.png)
更新时间:2020-04-03 13:56:17
|
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【推荐2】某学校为了解全校学生每天锻炼身体所花时间的情况,从全校随机抽取了100名学生进行调查,并将这100人的锻炼时间分组:第1组
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![](https://img.xkw.com/dksih/QBM/2022/1/16/2895808602750976/2897132653281280/STEM/4de2516e-b9f5-41ca-854f-86fb568b357d.png?resizew=219)
(1)根据频率分布直方图,估计该校学生每天锻炼身体的时间的众数与中位数;
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/149244df42e8354b35e4e531c1616ba0.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1720e1256b8eb4fa308d77814edaf197.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ab53811235a6aee1c8a7908983b7ce7.png)
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解题方法
【推荐1】利用展开式
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;
(3)把(2)中化简后的结果作为an,求
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b42cbbd3f04c42d57476ec45e59bcb4.png)
(1)求(1+2x)10的展开式中x4的系数;
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93b3bf23a0d6862f18b528770f5f7e7e.png)
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解题方法
【推荐2】(1)计算:
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(3)猜想
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名校
【推荐2】我们称
(
)元有序实数组
为
维向量,
为该向量的范数,已知
维向量
,其中
,
,记范数为奇数的
维向量
的个数为
,这
个向量的范数之和为
.
(1)求
和
的值;
(2)当
为正偶数时,求
的通项公式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2717a7f45d02b52829d1c9f0a7bdd53.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cfeacc29e6a61c5b3b4e439c0a91df.png)
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(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3b9e816b14051f785aa5aae72b8eed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a71fc9c0068109dad1382354570665.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cfeacc29e6a61c5b3b4e439c0a91df.png)
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