1 . 对于实数
,用
表示不超过
的最大整数,例如
,
,
,设x为正实数,若
为偶数,则称x为幸运数.在区间(0,1)中随机选取一个数,它是幸运数的概率为__________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dba82c9b34eaae7374d8f9bbb6abb141.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae9feb047004eb507de484a7f8c5b6a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19ba98f22c3380eeb7b9323fa487c7c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17a30f271f7b5f08bd81cab2089bb4e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cfe4ffba1ab1f41d416362ee281ac10.png)
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2019-01-29更新
|
536次组卷
|
2卷引用:2018年全国高中数学联赛天津市预赛
2 . 若
为正实数,且
是奇函数,则不等式
的解集是_____________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd2c2e8cc7b2a65022fe13d65766c6a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a9528968623f1427a7fae32c2371ed1.png)
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名校
3 . 下面左边的平行四边形ABCD是由6个正三角形构成,将它沿虚线折起来,可以得到如右图所示的粽子形状的六面体,在这个六面体中,AB与CD夹角的余弦值是( ).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/f0fb3eee-8dc4-47fb-aef7-72f53cf25b76.png?resizew=216)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/f0fb3eee-8dc4-47fb-aef7-72f53cf25b76.png?resizew=216)
A.0 | B.1 | C.![]() | D.![]() |
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2019-01-29更新
|
319次组卷
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2卷引用:2018年全国高中数学联赛天津市预赛
4 . 已知函数
和
的定义域都是
,则它们的图像围成的区域面积是________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b923078510697d5f7f9ea392eb76dd9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98d53cfbdaf39813b909c8883d9d2e3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/955fade76485dacdee5d82108d9c58c3.png)
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5 . 在以下四个数中,最大的是( )
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2019-01-29更新
|
548次组卷
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3卷引用:2018年全国高中数学联赛天津市预赛
6 . 定义区间
的长度均为
.已知实数
.则满足
的
构成的区间的长度之和为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d9128eea388668d5a9652afc8c5e7fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9de374592100c57865a606a2d21ece9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432d77fe5ad3032d59a237dd94c8a638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa0653197cd4a5e31febc2173404ce2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
A.1 | B.![]() | C.![]() | D.2 |
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2005高三·天津·竞赛
7 . 设集合
,其中
、
、
、
均为整数}.则集合
中所有元素的和等于( )种.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/884e780fb67034b407c5ea3f551325d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
A.1 | B.4 | C.7 | D.8 |
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2012高三·天津·竞赛
8 . 在正四面体
中,
、
分别是
、
的中点.则直线
和
所成角的余弦值是( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7785afeeaf274892253d04b4f693b367.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2012高三·天津·竞赛
9 . 设椭圆与
轴交于
、
两点,对于椭圆上不同于
、
的任意一点
,直线
与
的斜率之积均为
.则椭圆的离心率为( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3389f53711264b0acba3ba6019f8b908.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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