1 . 设点A的坐标为(0,3),点B、C为圆
上的两动点,满足∠BAC=90°,求△ABC面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc913bc204342a3c2e9d80d13078fb8c.png)
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名校
2 . 已知函数f(x)=xlnx-ax2,a∈R.
(1)证明:当1<x<3时,
;
(2)设函数F(x)=|f(x)|(x∈[1,e])有极小值,求a的取值范围.
(1)证明:当1<x<3时,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c7f197f4390616d2bfdee94fb2f15c4.png)
(2)设函数F(x)=|f(x)|(x∈[1,e])有极小值,求a的取值范围.
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2020-05-11更新
|
544次组卷
|
2卷引用:2019年全国高中数学联赛四川省预赛
3 . 设a,b,c∈(0,1],
为实数,使得![](https://staticzujuan.xkw.com/quesimg/Upload/formula/504819e52e43d1fae7fb261d4f809c02.png)
恒成立,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/504819e52e43d1fae7fb261d4f809c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09ff75538fd528697d98fa5ad61bba38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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4 . 已知:
.求证:
(1)若
,且
,则 ![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b8f6bf5c2f04c84550957271c5cb115.png)
(2)当
时,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d17e3231e8d07e6f17cca273949d2bbc.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb7961cbe98aac6a5fdee94582c341b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f364bd19eda02fa19a278441b2aa401b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b8f6bf5c2f04c84550957271c5cb115.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10e468312d09c6563c9094b710a35a65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eadd42e1f5910bcf2080d46d60db4f91.png)
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5 . 已知数列
满足
,
满足
.证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29518f13a1ebc3fff8181c2d7cfba22f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfd82633c81468682e43a48c4de02904.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2448cf72af76b810310e4cfb9818e2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50b25e60fe7b3d370e480fba715eb47c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92b8f281985adbb0bf5d8c37816336a2.png)
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6 . 如图,已知三棱柱
的底面是边长为2的正三角形,侧棱
与下底面相邻的两边AB,AC均成45度的角.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/64efc1c0-f4c7-4671-868f-f0b9c9597fa8.png?resizew=146)
(1)求点
到平面B1BCC1的距离.
(2)试问,当
为多长时,点
到平面
与到平面
的距离相等.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a9ad711b25c36dae0c2a2cedff9954.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/64efc1c0-f4c7-4671-868f-f0b9c9597fa8.png?resizew=146)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
(2)试问,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f96c673a2381f118ea2d3efc0bca1f3.png)
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7 . 设G是紧夹在平行线
与
之间的任一凸区域(即其边界上任意两点之间所连线段都包含于它的区域),其边界
与
和
都有公共点.平行于
的直线
将G分为如图所示的
两部分,且l与
和
之间的距离分别为a和b.
(1)G为怎样的图形时;
两部分的面积之比
达到最大?并说明理由.
(2)试求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
(1)G为怎样的图形时;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e329e98076754d6c75c7a29caa43c55.png)
(2)试求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e329e98076754d6c75c7a29caa43c55.png)
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8 . 已知数列
满足:
,若对任意正整数
,都有
,求实数
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06c568e405619a4623bffcd8a03dab37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a76ca08fb2d8577f0b0e5b16e5c98693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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9 . 设
为正实数,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3fb0c9c7e30bbc0ec8c3521577ee4fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c49ade0a2cb4677b858600fadff8f4b.png)
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