名校
1 . 已知
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37a3bf6d2baa5debc00a2399b9d570aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e4487468ab2823d6dbf7f0ebd2eb38.png)
A.7 | B.6 | C.5 | D.4 |
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名校
解题方法
2 . 三棱锥
中,已知
,
,
,则平面
与平面
所成的锐二面角的余弦值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d65639672f444b3d4dc6fc4f357ddbd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0ce06dbe9e1177468781ba4aff85ffc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5469318165ce841ae6d790b8cb4b343c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecfe1bf6f7bfe17f9bd28e97b0147f6.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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名校
3 . 在
中,
,则“
”是“
”的( )条件
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a36ec31cfd615abfbee3ed2f4a1d8883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc52358578b0beea452f1cea25dcd920.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09eebab59213386449a726b75065bf76.png)
A.充要 | B.充分不必要 | C.必要不充分 | D.既不充分也不必要 |
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4 . 已知复数
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef015c99536d13f1386bbb9a1dcaecea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95316769aa8c8a67e04c232fdb904433.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d778416183da9ba9a7bd872cc9a76806.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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名校
5 . 已知圆C:
,圆心为O,直线
与C交于A,B两点,则
的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5f5d967ad135991b6075ee45df55643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33ff0cf397644bd8215a6d8206913e6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad5ff8b799020dd96e7d905e046c55f2.png)
A.![]() | B.![]() | C.11 | D.9 |
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名校
解题方法
6 . 函数的凹凸性是函数的重要性质之一.函数凹凸性的定义:函数
在区间
内可导,
是
内任一点.若曲线弧上点
处的切线总位于曲线弧的下方,则称曲线弧在
内是凹的;若曲线弧上点
处的切线总位于曲线弧的上方,则称曲线弧在
内是凸的.函数
在区间上为凹(凸)函数等价于
的导函数在区间上单调递增(递减).若
在定义域内是凹函数,则
的最小值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43db00e106c7d08a76a7ba71ca5e63d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43db00e106c7d08a76a7ba71ca5e63d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e689ffca137d7d00abefe436b1a83a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
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7 . 已知集合
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cbfb2a02893fdb9b746c988f4e965ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ecffcf87cc612a54aef915895d08cf7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4b9b470218359a4a47be9244980489e.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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8 . 三人相约晚上一起点某餐厅外卖,他们分别在
,
,
平台上查到该餐厅的评分情况.
有20人评价,评分的平均分是6分,方差是1.
有30人评价,评分的平均分是7分,方差为
.
有50人评价,评分的平均分为5分,方差为
,那么该餐厅总的得分方差是( )
![](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/8ec818fc0754296163206e1e8870f9e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb8f58755aee89fb2cf72ba518dcee2a.png)
A.1 | B.1.45 | C.2 | D.1.86 |
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9 . 已知
为抛物线
上一点,点
到
的焦点的距离为18,到
轴的距离为12,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82ea1be9b9b6bb12afa7e1ce703d1603.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df5be1440d099f464ef46dee39de6010.png)
A.6 | B.8 | C.10 | D.12 |
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名校
解题方法
10 . 已知集合
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe50b6715e229fd97d3fad675ff7cd27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4b9b470218359a4a47be9244980489e.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次