如图,已知三棱柱
中,平面
平面ABC,
,
.
![](https://img.xkw.com/dksih/QBM/2020/7/9/2502377418481664/2504067813048320/STEM/87d920da95854bd1a8341b8cc0f194ce.png?resizew=178)
(1)证明:
;
(2)设
,
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46fe926770d2354e172dec02f5ce2efe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://img.xkw.com/dksih/QBM/2020/7/9/2502377418481664/2504067813048320/STEM/87d920da95854bd1a8341b8cc0f194ce.png?resizew=178)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47af45fbf1714055d9b414a44a8613fa.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8c563906d6d25078fd5d96abe96194.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e718d2042232538370f5168f7eb9a1.png)
更新时间:2020-07-12 06:41:55
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】三棱柱
中,
为
的中点,点
在侧棱
上,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/a400efb2-b1e7-4413-8557-ed2a1e0d35a0.png?resizew=194)
(1)证明:
是
的中点;
(2)设
,四边形
是边长为2的正方形,四边形
为矩形,且
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ede6a60cad0e0b58e1549fda6e085719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b094e639c2b31dc54b1b3e6456e77843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7440b41636c761b0910639e310ff7dfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0645ae6945ac2f5e75bd58f00634be7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/a400efb2-b1e7-4413-8557-ed2a1e0d35a0.png?resizew=194)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b094e639c2b31dc54b1b3e6456e77843.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67cb74fcd7479c3eddf21dbff36e1567.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc0e453266a802c430a748aa310c38cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce731cd45eb83b75e47e20551a97cd45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18fbae6c175f6875fae2dcd6cfa7f7ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e68893f7873cbff9f8a0dc79bae167.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】在平面
内的四边形
(如图1),
和
均为等腰三角形,其中
,
,
,现将
和
均沿
边向上折起(如图2),使得
,
两点到平面
的距离分别为1和2.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/5668ce7f-8390-4223-84f1-1a682b6bb103.png?resizew=383)
(1)求证:
;
(2)求二面角
余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e45b0e1c3f6f5bc4cc81290bf263d90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/647f568811a78aefb041f7002d740524.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/5668ce7f-8390-4223-84f1-1a682b6bb103.png?resizew=383)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70734a8e672376bb0bd1522e229f86a2.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f1854ba6cc92481d7a616bd2788a47e.png)
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解答题-证明题
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名校
解题方法
【推荐1】如图,在四棱锥P-ABCD中,底面ABCD是边长为2的菱形,PA⊥平面ABCD,∠ABC=60°,E为BC的中点,F为边PC上的一个点.
(1)求证:平面AEF⊥平面PAD;
(2)若H为PD上的动点,EH与平面PAD所成角的正切值的最大值为
,求平面PAB与平面PCD夹角的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/17/b7ad1b1c-9565-4b7f-8ccf-470ea7e38958.png?resizew=159)
(1)求证:平面AEF⊥平面PAD;
(2)若H为PD上的动点,EH与平面PAD所成角的正切值的最大值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/839c7616cd0d90265f4b2c9c021254fe.png)
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解答题-证明题
|
适中
(0.65)
【推荐2】已知在四棱锥
中,底面
是矩形,且
,
平面
,E、F分别是线段
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/4/e7c76a56-83c9-42ab-b372-ae26f72d63dc.png?resizew=159)
(1)证明:
;
(2)在线段PA上是否存在点G,使得
平面
,若存在,确定点G的位置;若不存在,说明理由;
(3)若PB与平面
所成的角为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13da96a673bb7d70c301e333b4ca994.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/4/e7c76a56-83c9-42ab-b372-ae26f72d63dc.png?resizew=159)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fb2fbbce7207d2b2bdd5c5ab61ecd04.png)
(2)在线段PA上是否存在点G,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1399e7ae0b2decaafc62a5cdffb15522.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0901e2f5cefe6468cbbcaa332287d63.png)
(3)若PB与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d32c6f1f2d12161619aa3d15197ee5.png)
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解答题-证明题
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适中
(0.65)
【推荐3】已知如图1所示等腰
中,
,
,
为
中点,现将
沿折痕
翻折至如图2所示位置,使得
,
、
分别为
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/17/337cdde8-136c-42ef-9dc1-02109044e99a.png?resizew=374)
(1)证明:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3c65edad25ddd666cdce0d7e5afefc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a566b100fb2ebe3d208f9b6527934218.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83cb6327dcbc8a998e6586bcfa7a3b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8878eae05fba3ac75d733695959af67f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/17/337cdde8-136c-42ef-9dc1-02109044e99a.png?resizew=374)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/963a91995abd4927d75406d16e10a81f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/053932dc8c5eebbc739256cb4de6c71d.png)
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