如图,四棱锥
的底面
是梯形,
,
,E为AD延长线上一点,
平面
,
,
,F是PB中点.
(1)证明:
;
(2)若
,三棱锥
的体积为
,求锐二面角
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/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db807b09cc550f476b3f8fa0c6a14425.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/885020440f20b5fc2f91ac373ffa004e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a60023f7a8c7310dfad0b55a5266977c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/12/fbc31e23-168a-4b75-a21d-e0759a348e12.png?resizew=144)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc2484662ae40c406b054d14a7f9e118.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7ea9d92e5c258a50af1e461c7388894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c4188199c6db7e447f1b642e4997044.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61bfc65bfbc357d43069e9aad18f8625.png)
更新时间:2023-07-09 22:15:48
|
相似题推荐
【推荐1】已知正四棱柱
中,
,
、
分别是棱
、
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/2229c393-3d4e-46bc-8192-679fbc552076.png?resizew=176)
(1)若
,求直线
与直线
所成的角;
(2)若
,设点
到平面
的距离为
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26b4f0b6a69ee5192370239c6fdd7b3d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/5/2229c393-3d4e-46bc-8192-679fbc552076.png?resizew=176)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ad3a1ea6790177130e16c2124984087.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d33da711e50e96568facb18cef27165.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba9e20d667d04bf3ee7f55cc795ce01.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
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解题方法
【推荐2】一幅标准的三角板如图1中,
为直角,
,
为直角,
,且
,把
与
拼齐使两块三角板不共面,连结
如图2.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/0ebda17c-3f5b-4658-9b22-49108410c4ac.png?resizew=409)
(1)若
是
的中点,
是
的中点,求证:
平面
;
(2)在《九章算术》中,称四个面都是直角三角形的三棱锥为“鳖臑”,若图2中
,三棱锥
的体积为2,则图2是否为鳖臑?说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b8b98b2f83279a49e94d9f48c5e6f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3b0b11a80e8b107e55534d7fda9f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4a288554fe25fe0a72530eb29756e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d47a70a2811c174e73ce1beeb80c75c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/0ebda17c-3f5b-4658-9b22-49108410c4ac.png?resizew=409)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d56640274c077e5b779cccde87a2d5f.png)
(2)在《九章算术》中,称四个面都是直角三角形的三棱锥为“鳖臑”,若图2中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51f73a0ca4e6c794242489066fddb6c5.png)
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【推荐1】如图,三棱锥
中,底面
为直角三角形,
,
为
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/2021/3/25/2685611862204416/2687049493987328/STEM/d6584f285b6141dfbce4e87115232da8.png?resizew=320)
(1)求证:
平面
;
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a351136b18bc7d3bd5122332772ab23b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4edeb0136a286cd638b7e4e3bbe8726e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60334b062acf697efaa4f3f7087a80dc.png)
![](https://img.xkw.com/dksih/QBM/2021/3/25/2685611862204416/2687049493987328/STEM/d6584f285b6141dfbce4e87115232da8.png?resizew=320)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
解题方法
【推荐2】如图1,已知正三角形
边长为6,其中
,
,现沿着
翻折,将点
翻折到点
处,使得平面
平面
,
为
中点,如图2.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/31/de0a2edc-2253-4841-b1a8-4505c32a75a6.png?resizew=314)
(1)求异面直线
与
所成角的余弦值;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5c9ba21933a3ac9f13936183443e8d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/122fe84cfa345c1902231699c96beac2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d753c9a2cd3eeed8492f970face94db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dc0de4b875e8b4b67dc4c395d62d7e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eb97aff0960e2640314888a38e7169c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/31/de0a2edc-2253-4841-b1a8-4505c32a75a6.png?resizew=314)
(1)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a21897349d3d7c94419692106887153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b46c607b3deac746c0ef3389ad8f65c.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/719103f93166bab4828257608e641a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8c9aedf70a0d7dae193ec00ca059565.png)
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解题方法
【推荐1】如图,在四棱锥
中,
底面
,四边形
是直角梯形,
,
,点
在棱
上.证明:平面
平面
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7dd6f09284794d2c603823033940428.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1b523f9ea41acf2f5c5724a0824ae06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/677d1863ff4d8ac1604b18149d4f320f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://img.xkw.com/dksih/QBM/2024/2/26/3441459683860480/3448745100099584/STEM/bc39b1d965de4d5fb808b1665f7e7be4.png?resizew=214)
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【推荐2】如图所示的多面体中,EA⊥平面ABC,DB⊥平面ABC,AC⊥BC,CM⊥AB,垂足为M,且AE=AC=2
,BD=2BC=4,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/ca7eeabc-f9e1-4658-8b82-ca23fc0514a1.png?resizew=134)
(1)求证:CM⊥ME;
(2)求二面角A﹣MC﹣E的余弦值.
(3)在线段DC上是否存在一点N,使得直线BN∥平面EMC,若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c3f8c3ba00c59e0634ed10fa85289de.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/ca7eeabc-f9e1-4658-8b82-ca23fc0514a1.png?resizew=134)
(1)求证:CM⊥ME;
(2)求二面角A﹣MC﹣E的余弦值.
(3)在线段DC上是否存在一点N,使得直线BN∥平面EMC,若存在,求出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53737a3a23befc8640c0b92180f953dc.png)
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解题方法
【推荐1】如图,在棱长为3的正方体
中,点
在线段
上,点
在线段
上,且
,
.
(1)求点
到直线
的距离;
(2)求平面
与平面
所成二面角的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fd4c85bb98a2a0afddd7ed92578ad2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9df8d320bee31b074de41d98a662f9a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73021f964178d175673b6ff9fe2b8e0c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/24/78531bac-3a74-4027-98db-45ce0d1702a0.png?resizew=156)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3701229eb2365ce6746db26c1bcef9d7.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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【推荐2】在四棱锥
中,底面ABCD是矩形,
为BC的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/f85978d3-f058-46f4-b620-e768640abe5f.png?resizew=191)
(1)证明:
平面ABCD;
(2)若PC与平面PAD所成的角为30°,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6be2b61f4a38e2ee2c1a01e00b3ae6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/676aab822f6b92aaf84cd688acb7050d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65c929fed1d514a112dab659d514dd9b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/28/f85978d3-f058-46f4-b620-e768640abe5f.png?resizew=191)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afb18c7c5391647214d4da31a88202d2.png)
(2)若PC与平面PAD所成的角为30°,求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f09cf4f12bcfc80a91ebcbfc6e372ae6.png)
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【推荐3】如图,在四棱锥
中,
平面
,底面
为平行四边形,
,
,
,
,
为
上一点.
![](https://img.xkw.com/dksih/QBM/2020/7/13/2505229755547648/2506210916655104/STEM/a6196f5801b64eca9cf7af7a84cc3223.png?resizew=148)
(1)求证:平面
平面
;
(2)若
平面
,求面
与面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64e6efc6aba35f9448f804bbda8e346e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://img.xkw.com/dksih/QBM/2020/7/13/2505229755547648/2506210916655104/STEM/a6196f5801b64eca9cf7af7a84cc3223.png?resizew=148)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9a9d28727a2c2a04a679833b9d35ed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d923a338dd2d2e29336b42574d38448.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68d8f78683247c01bffad2296e78502b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53bdef2e7a7929ad6190302ab44c46c0.png)
您最近一年使用:0次