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
真题
解题方法
3 . 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
4 . 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
5 . 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
6 . 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
7 . 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
8 . 对于没有重复数据的样本
、
、…、
,记这m个数的第k百分位数为
.若
不在这组数据中,且在区间
中的数据有且只有5个,则m的所有可能值组成的集合为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad7f66c97bfce4c00c53d86700c961b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a76ca140172ecba82a7ec84c7a9d7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621649c6156ae32223bb79da9fbf959c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/110f64c0aa40f7455a016edd0dbb8ea1.png)
您最近一年使用:0次
名校
9 . 如图,河宽50米,河两岸A、B的距离为100米,一个玩具气垫船(不计大小)可以从A走水路直接到B,也可以从A先沿着岸边行驶一段距离,再走水路到B.已知该气垫船在水中的速度是10米/分钟,岸上的速度是20米/分钟,则从A到B的最短时间为______ 分钟,(精确到小数点后两位)
您最近一年使用:0次
10 . 某区域的地形大致如图
,某部门负责该区域的安全警戒,在哨位
的正上方安装探照灯对警戒区域进行探查扫描.假设
:警戒区域为空旷的扇环形平地
;假设
:视探照灯为点
,且距离地面
米;假设
:探照灯
照射在地面上的光斑是椭圆.当探照灯
以某一俯角从
侧扫描到
侧时,记为一次扫描,此过程中照射在地面上的光斑形成一个扇环
由此,通过调整
的俯角,逐次扫描形成扇环
、
、
.第一次扫描时,光斑的长轴为
,
米,此时在探照灯
处测得点
的俯角为
如图
记
,经测量知
米,且
是公差约为
米的等差数列,则至少需要经过______ 次扫描,才能将整个警戒区域扫描完毕.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5ac241a6a76fe5ef9e0c47b91022561.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b7f27ebcef70a3ebbbe8d2e53ea0896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3bb90d13cc04869fc775a0d6968191.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/227611549779ca023b28babcef9923d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc1a80ebe854959e85f8fbdb77407bdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a328e1537d7aba18bc124a9eec1664d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5d209fc21986b1a4052080df3d8ce2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dd366786b7de3ade35b1885491ba1f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/362e8af456b90ac6d7d540bef266eea1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5d3fddd78e7614c5e2169f109d7b0a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80a73681e29e5e4efa73194283da483f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a1fe314207f01f626ecec0a457030c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a87796ee30e6c5d5e6b6285b32abe10c.png)
您最近一年使用:0次