1 . 将正整数1,2,…,7任意分成两组,使得每组至少有一个数.则第一组数的和与第二组数的和相等的概率是_________ .
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2011高三·甘肃·竞赛
2 . 若底边长为2的正四棱锥恰内切一半径为
的球,则此正四棱锥的体积是_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
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2011高三·甘肃·竞赛
3 . 若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db38798bcdd49721fd28833dd2a633a.png)
_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e53d6c0ab4311ebb158df2c3a33edb30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db38798bcdd49721fd28833dd2a633a.png)
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2011高三·甘肃·竞赛
4 . 已知集合
.则
的非空子集的个数为_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb2226bea1157eff9caa36f222099abd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
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2013高三·甘肃·竞赛
5 . 已知
、
、
为正实数.证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a69cf695e9a178a75ac6829a37b4bac.png)
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2013高三·甘肃·竞赛
6 . 已知
是数列
的前
项和,且
.
求:(1)
与
之间的关系式;
(2)使得数列
递增的所有
的取值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/700af50ae9abcdd7c9877d71265f9c0d.png)
求:(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7230de53663c75658c58bbf206a0085.png)
(2)使得数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4e6f8b983bb6ede54a6371916832e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f7dcce39f3d4dc6b7faf84dc1d0a1.png)
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2013高三·甘肃·竞赛
7 . 已知椭圆
:
的一个焦点为
,且过点
.设椭圆
的上、下顶点分别为
、
,
是椭圆上异于
、
的任一点,直线
、
分别与
轴交于点
、
.若直线
与过点
、
的
相切,切点为
,证明:线段
的长为定值,并求出该定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dd54b9df3402ad91e2d34c40efe0c7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17618d8d22ebb3fd6835a7eb139b4f95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27208f7c8d1f32587bcb0a52dbc40c56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3b9e816b14051f785aa5aae72b8eed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3b9e816b14051f785aa5aae72b8eed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/800c5e266b4ad8462a46970f0a232d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f46b053f98b1d05a2043e94eeaefea87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.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/be99fa94a1f3e4964fcc13a14fab9ba5.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/d3ae3c0fbf7d162b0293a03c29c027fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be99fa94a1f3e4964fcc13a14fab9ba5.png)
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2013高三·甘肃·竞赛
8 . 设
表示不超过实数
的最大整数.则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9bc07682560c8d7c135b4f40757eff3.png)
_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4f5908d6a1217e493ed7586b6964dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9bc07682560c8d7c135b4f40757eff3.png)
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2013高三·甘肃·竞赛
9 . 设
是定义在
上的增函数,且关于
的不等式
恒成立.求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7dcdd87d593df4a5c5e98d47fe1cfa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4b53d77902db40df286d338af7a2c4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
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