2007高三·天津·竞赛
1 . 方程
的所有正整数解为______________________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12559d78c032ee744b9e87fb35a9098e.png)
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2007高三·天津·竞赛
2 . 过四面体
的顶点
作半径为1的求,该球与四面体
的外接球相切于点
,且与平面
相切.若
,
,
,则四面体
的外接球的半径
为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d4746df85049d1651d3f6c30212a7a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2163a2634041c4f809051f99035cc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
A.2 | B.![]() | C.3 | D.![]() |
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2007高三·天津·竞赛
3 . 已知
为正整数,实数
满足
.若
的最大值为40,则满足条件的数对
的个数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09b7c53184c7309b75b35cde8a194741.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2e647c14561826ba9e396acc5a3792c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76bd37366fd56866122eef34e2fbd17d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88584cf1df43e28d03592c7998b1653.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
A.1 | B.3 | C.5 | D.7 |
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2007高三·天津·竞赛
4 . 正2007边形
被它的一些不在
内部相交的对角线分割成若干个区域,每个区域都是三角形.则锐角三角形的个数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
A.0 | B.1 | C.大于1 | D.与分割的方法有关 |
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2007高三·天津·竞赛
5 . 已知关于参数
的二次函数
的最小值是关于
的函数
.则
的最小值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70444e3a66d1068038c5b5a77c7954aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c57c6462f38b71ac9e6a482e44c2134.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f484115a9df1b6060d6b14df85c6f38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f484115a9df1b6060d6b14df85c6f38.png)
A.-2 | B.![]() | C.![]() | D.以上结果都不对 |
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2007高三·天津·竞赛
6 . 方程
的实数解的个数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92f74b7466554f8298cbbf0a6370985e.png)
A.0 | B.1 | C.2 | D.大于2 |
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7 . 满足
的正整数解
构成的集合是________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/497a0a266661dbfc783a13457883f90d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
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8 . 若
是一个由数字1,2,3,4,5,6,7,8,9组成的
位正整数,并同时满足如下两个条件:
(1)数字1,2,…,
在
中各出现两次;
(2)每两个相同的数字
之间恰有
个数字.
此时,我们称这样的正整数
为“好数”.例如,当
时,
可以是312 132.试确定满足条件的正整数
的值,并各写出一个相应的好数
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d51f9147b8265c0276c1f2c2659197.png)
(1)数字1,2,…,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
(2)每两个相同的数字
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b640c28d4f3afbf94d07ec2e4d98b06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
此时,我们称这样的正整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
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2005高三·天津·竞赛
9 . 已知椭圆
,其长轴为
,
是椭圆上不同于点
、
的一个动点,直线
、
分别与同一条准线
交于
、
两点.试证明:以线段
为直径的圆必经过椭圆外的一个定点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dd54b9df3402ad91e2d34c40efe0c7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/800c5e266b4ad8462a46970f0a232d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b104090ea2ac34be58a76a4e0e95cb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/123a6eaa56d0b9bd254c6d1361d9114c.png)
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