如图,在正方体
中, E、F分别是
,CD的中点,
![](https://img.xkw.com/dksih/QBM/2021/10/2/2820856675655680/2822206894743552/STEM/4bfe29149fb241baaf8c50e0466d4f16.png?resizew=251)
(1)求证:
平面ADE;
(2)求向量
的夹角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/2021/10/2/2820856675655680/2822206894743552/STEM/4bfe29149fb241baaf8c50e0466d4f16.png?resizew=251)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f36df8302f33f07a69cef14c3b822902.png)
(2)求向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23bd9ba74ab8c7f30688a0b724d51562.png)
更新时间:2021-10-04 18:17:32
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相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图所示,在四棱锥
中,
为等腰直角三角形,且
,四边形ABCD为直角梯形,满足
,
,
,
.
;
(2)若点E为PB的中点,点M为AB上一点,当
时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c025ee3317be1099b7bf03a11e37ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa3f47f7c8e18b5e501c9bddeda0a547.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce4ab7e657f01bdfa235f8c4d6681d13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cd60919c09876f29ff699b790f701f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58ff26d9121c651ed648f0eafe293fd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6c996b7688b88d9df08c2f6508be46e.png)
(2)若点E为PB的中点,点M为AB上一点,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cd73c19b1eb4bbb11efac224aa29e97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6744bbb4c871543896dd2a8acbe297c3.png)
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【推荐2】已知
,
,求:
(1)
,
,
;
(2)
+
与
+
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a9e5d3976823577abfe9aac5146a481.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/407510860cb5addb44b34eb60a604de4.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb80eb942aafb194fadc473776f35b1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/433b94c39737727e53468df419d8314a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb80eb942aafb194fadc473776f35b1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/433b94c39737727e53468df419d8314a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
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解答题-问答题
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【推荐1】如图,在长方体
中,
,
,点
在棱
上移动.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/acf8600e-1480-4ebd-9f97-a5b6dd45fa90.png?resizew=203)
(1)证明:
;
(2)当
时,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7d64fc81c857b124268609a8beb77b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/acf8600e-1480-4ebd-9f97-a5b6dd45fa90.png?resizew=203)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0fa81c1f81266b4ef3d471bc6bfc38d.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8a2d7fc766cfa5d364fd9520f00c20e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/122f1119ef7ec9b4ccbd835a2376d117.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
解题方法
【推荐2】如图所示,在直四棱柱
中,底面
为等腰梯形,
,
,
,
,
,
,
分别是棱
,
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/1eadf4e5-82ba-4999-92b8-c206d7c2062f.png?resizew=158)
求证:(1)直线
平面
;
(2)平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08ad8d16722f5b9e7fd2602f14d5ffbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/522230546d4b802094e86ceb48c2ba38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/1eadf4e5-82ba-4999-92b8-c206d7c2062f.png?resizew=158)
求证:(1)直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40d1377302142bb5f514819729edbe5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a456b9e47c1dc1ca65494bf60518994b.png)
(2)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6508981f33a8270e213c71f8856193d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a456b9e47c1dc1ca65494bf60518994b.png)
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解答题-证明题
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适中
(0.65)
名校
【推荐3】如图,在正方体
中,棱长为
分别是
的中点.
(1)证明:
.
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd21f1df5df752343fd02502854eacb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd94e1bd480758d8ef0cd553e0361e62.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/12/a0debf21-a1d8-41ce-8460-b6d8b1a285f2.png?resizew=167)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f838933ac032270e24d15265461a89bd.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dab8375daa062d56ac9dcd77eebcf9f4.png)
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