名校
1 . 如图,已知矩形
的对角线交于点
,将
沿
翻折,若在翻折过程中存在某个位置,使得
,则
的取值范围是( )
![](https://img.xkw.com/dksih/QBM/2022/5/25/2987260603670528/2987719801765888/STEM/98aeeeee-15fc-4e7b-88e2-38c927d4fd3b.png?resizew=105)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72e34419a5fcb6d4eec2f01e5f99aa1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b4424cb0af429b92e1fc168c4c70de4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://img.xkw.com/dksih/QBM/2022/5/25/2987260603670528/2987719801765888/STEM/98aeeeee-15fc-4e7b-88e2-38c927d4fd3b.png?resizew=105)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
2022-05-26更新
|
2083次组卷
|
6卷引用:浙江省杭州高级中学2022届高三下学期5月仿真模拟数学试题
浙江省杭州高级中学2022届高三下学期5月仿真模拟数学试题浙江省金华十校2021-2022学年高一下学期期末模拟数学试题浙江省绍兴市鲁迅中学2022-2023学年高二普通班上学期期末模拟数学试题(已下线)第30练 空间向量的应用(已下线)专题16 空间向量及其应用(模拟练)(已下线)专题07 立体几何小题常考全归类(精讲精练)-2
解题方法
2 . 如图,几何体
中,平面
平面ABC,
,
,
.
![](https://img.xkw.com/dksih/QBM/2022/3/23/2942508286009344/2943028567359488/STEM/9f53c1dd67f9498092dea16e6902bc97.png?resizew=245)
(1)证明:
;
(2)若
,
,求直线DA与平面EAB所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bde1e200d1dd5ddc433c876c9d2f688c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9332278351ab92e03e984e9279dd06a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3a6dcaf9f9e9a940b4a16f7ec2fc2d.png)
![](https://img.xkw.com/dksih/QBM/2022/3/23/2942508286009344/2943028567359488/STEM/9f53c1dd67f9498092dea16e6902bc97.png?resizew=245)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd260fb9d772c122dcb1df52cbe38ab.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c776123acaded2ccf842d180b9f7741a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b547d886c528fa2c63016c217b8fb51.png)
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3 . 我国近代数学家苏步青主要从事微分几何学和计算几何学等方面的研究,在仿射微分几何学和射影微分几何学等研究方面取得了出色成果.他的主要成就之一是发现了四次代数锥面:对于空间中的点P(x,y,z),若其坐标满足关于x,y, z的四次代数方程式,称点P的轨迹为四次代数曲面.若点K(1,k,0)是四次曲面
:
上的一点,则k=___ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95c37f002b6dceef655b0dbd9582e476.png)
您最近一年使用:0次
2022-02-08更新
|
745次组卷
|
6卷引用:浙江省“数海漫游”2021-2022学年高三上学期第二次联考数学试题
浙江省“数海漫游”2021-2022学年高三上学期第二次联考数学试题(已下线)专题38:空间向量及其运算 -2023届高考数学一轮复习精讲精练(新高考专用)广东省惠州市博罗县2022-2023学年高二上学期期中数学试题3.1空间直角坐标系测试卷-2022-2023学年高二上学期数学北师大版(2019)选择性必修第一册(已下线)第六章 突破立体几何创新问题 专题一 跨学科交汇问题 微点3 跨学科交汇问题综合训练【培优版】甘肃省武威市凉州区2023-2024学年高二下学期期中质量检测数学试卷
名校
4 . 已知三棱锥
中,
,且
,长度为1的线段
的端点
在
上,端点
在侧面
内运动,若
的中点为
,
的重心为
,则
的最小值是_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81ff2c282e317373b88cb632ad96b195.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f7baa13630f448b194478cb862e620f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ced36ad180a287548ea22cbf5ddb746.png)
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名校
5 . 已知直三棱柱
的侧棱长为6,且底面是边长为2的正三角形,用一平面截此棱柱,与侧棱
,
,
分别交于三点
,
,
,若
为直角三角形,则该直角三角形斜边长的最小值为( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.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/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed283a253b61df01f2a1cdc0cd8003f3.png)
A.2 | B.4 | C.![]() | D.![]() |
您最近一年使用:0次
2020-06-08更新
|
547次组卷
|
2卷引用:浙江省宁波市镇海中学2018届高三下学期5月模拟考试数学试题
解题方法
6 . 在四棱柱
中,
平面
,底面
是边长为
的正方形,侧棱
的长为
,
为侧棱
上的动点(包括端点),则
![](https://img.xkw.com/dksih/QBM/2015/7/1/1572159116730368/1572159122382848/STEM/adb2ca5c-2d20-4fb3-a528-0b80c8d26a96.png?resizew=140)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/2015/7/1/1572159116730368/1572159122382848/STEM/adb2ca5c-2d20-4fb3-a528-0b80c8d26a96.png?resizew=140)
A.对任意的![]() ![]() ![]() ![]() |
B.当且仅当![]() ![]() ![]() |
C.当且仅当![]() ![]() ![]() |
D.当且仅当![]() ![]() ![]() |
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