1 . 设
为大于2的自然数,将二项式
两边同时求导,可以得到一些特别的组合恒等式
,结合课本中杨辉三角研究方法,可以得到![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35f15fc276a46463377bcecb7c6e174b.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb174c123cb7dd2d47237adc5b17acae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5ee37c0c6e04fe8d2647b7563243e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35f15fc276a46463377bcecb7c6e174b.png)
您最近一年使用:0次
2 . 考虑
的非空子集
,满足
中的元素个数等于
中的最小元素,例如,
就满足此条件. 则这样的子集
共有______ 个.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/477aaa8eb4961a77a717ee664fd021ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/765272efc14488ec658fc3302c5e6cc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
您最近一年使用:0次
名校
解题方法
3 . 已知有5个男生和
个女生,若从中选择2个男生和1个女生在狂欢节中表演一个小品节目,共有30种不同的选法,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
您最近一年使用:0次
真题
解题方法
4 . 设集合
中的元素皆为无重复数字的三位正整数,且元素中任意两者之积皆为偶数,求集合中元素个数的最大值______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
您最近一年使用:0次
真题
5 . 某校举办科学竞技比赛,有
3种题库,
题库有5000道题,
题库有4000道题,
题库有3000道题.小申已完成所有题,他
题库的正确率是0.92,
题库的正确率是0.86,
题库的正确率是0.72.现他从所有的题中随机选一题,正确率是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38335830b93ac4d99c28a8e209eecb3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
您最近一年使用:0次
6 . 已知点B在点C正北方向,点D在点C的正东方向,
,存在点A满足
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/451edc75de74313e53f5d636ac930848.png)
______ (精确到0.1度)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a16dc02090b6e9263555061f14fbc8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d381171dbde5c1ff4d8a09c178ab6f4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/451edc75de74313e53f5d636ac930848.png)
您最近一年使用:0次
名校
7 . 设关于x的方程
的从小到大的第i个非负解为
,若数列
是无穷等差数列,且
在区间
中的项恰好比在区间
中的项少2项,则ω的取值集合为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab4aef8fc10674359b41c70424c7b696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f45016247370f5b00aeb0882977abb8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5265d99095b635f62c7915298ec0e963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/583dfca240679328ffcbbe457ec5bdd8.png)
您最近一年使用:0次
名校
8 . 某企业欲实现在今后10年内产值翻两翻的目标,则该企业年产值的年平均增长率为____________ (结果精确到0.001)
您最近一年使用:0次
名校
9 . 日常生活中,较多产品的包装盒呈正四棱柱状,烘焙店的包装盒如图所示,正四棱柱
的底面ABCD是正方形,且
,
.
的方向捆扎包装盒会比按照图B中的十字捆扎法更节省彩绳(不考虑打结处的用绳量和彩绳的宽度).则图A比图B最多节省的彩绳长度为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad1a56baf43ffdf67bc8460856e31fec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83c210b2f9961cf5915eafd7815e505.png)
您最近一年使用:0次
名校
解题方法
10 . 在锐角
中,
,它的面积为10,
,
,
分别在
、
上,且满足
,
对任意
,
恒成立,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/345078b37bdf02f53100140507c85bde.png)
___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6168bceb8119e8e2290ccc35b6ccc0e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc57614c316ede4c0a0ab3d533e21bd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/721fc29059eafb153d24020dbaefee29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd59a5621e55f43dd7e78aa7cbfaffae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f370a1d4dd341e5ab1774a66c66c1204.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/345078b37bdf02f53100140507c85bde.png)
您最近一年使用:0次