已知在三棱柱
中,底面
是正三角形,
底面
,
,
,点
,
分别为侧棱
和边
的中点.
![](https://img.xkw.com/dksih/QBM/2022/10/20/3091998839209984/3092649987022848/STEM/3d32ae83bab24277a820009a1cd2653d.png?resizew=135)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36cf3bff56a7f4ab6c0008e90823025d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/854f480c60b88b546cb15d3b5622e212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3073a50d7c1b9b4d6e213576c42c2d85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f93edbd735d79524f463085a4e9093bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81847012eb370abf85e43790d0de760b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252053b853152bd294a8315debd00b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/655b6a742dbacdab5aaa298007663dd4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86814dbae9a5343d69bb4647900b3bfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b10b969819d397711310c8dbb399ebc.png)
![](https://img.xkw.com/dksih/QBM/2022/10/20/3091998839209984/3092649987022848/STEM/3d32ae83bab24277a820009a1cd2653d.png?resizew=135)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d73133e50823f13346b34ca27007526f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2682c803715e34aa35f0d714e2b2c225.png)
更新时间:2022-10-21 20:35:25
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图所示的五面体
为直三棱柱
截去一个三棱锥
后的几何体,
,
,D为
的中点,E,F分别为
,
的中点.
(2)设
(
),是否存在
,使得平面ABC与平面PBF夹角的余弦值为
?若存在,请求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3886925ab2e7b8bd754388eff910ddb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86f0c01cdd682431365cf43dfba98bdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb717228e1762d335814a3adc90eae45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93ecad355286188fd317939fa50f9555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89f85edf697138a58f99f82ebedbba6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd3ede869e508a8c8bda34a16782f863.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a734873a608f0c070dec80b89d179754.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
解答题-证明题
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解题方法
【推荐2】如图,在四棱锥
中,
底面
,底面
是正方形,
,
分别为
的中点.
![](https://img.xkw.com/dksih/QBM/2012/2/11/1570730888454144/1570730894032896/STEM/256e8e2c5a704b59b0b46a5b023b8847.png?resizew=155)
(1)求证:
;
(2)求
与平面
所成角的正弦值;
(3)在平面
内求一点
,使
平面
,并证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.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/43d4c42112e0a22f240ce2ae432e5b4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40c2013527c6089d7df59bca21a4598c.png)
![](https://img.xkw.com/dksih/QBM/2012/2/11/1570730888454144/1570730894032896/STEM/256e8e2c5a704b59b0b46a5b023b8847.png?resizew=155)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b6cc3789c0e9b7d1226aa0de3327599.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
(3)在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36148e5b0d89ba45bd98b91da00bf2b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b60870baa5e3fbc33a749aa5f0a94be.png)
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适中
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【推荐3】如图,
且
,
,
且
,
且
,
平面
,
.
(1)若M为CF的中点,N为EG的中点,求证:
平面
;
(2)求二面角
的余弦值;
(3)若点P在线段DG上,且直线BP与平面
所成的角为
,求线段DP的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e839ac941e8bf536ff35a12e56c7a400.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdc143c7fd7c471ca91b6ccc22438fdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66514e4d9ad91dbc0cc4330de68a29e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fee573ad62dc536a05dadf5008f1afb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/755d575f0a87f3345e232b66d5956070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cf187bc2ede965870b90757b495f53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81b091ee5a8b32424b2b836dde7860c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/3/49e0f005-4891-4a18-8cfa-75ae83f0386b.png?resizew=167)
(1)若M为CF的中点,N为EG的中点,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a8d99c75180422fecf6d3f3d2910b34.png)
(3)若点P在线段DG上,且直线BP与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50cfd99a702ee24f9ef94e4b6f50101f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
您最近一年使用:0次
解答题-证明题
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名校
【推荐1】如图,棱长为
的正方形
中,点
分别是边
上的点,且
将
沿
折起,使得
两点重合于
,设
与
交于
点,过点
作
于
点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/11/9dd264e9-8795-480e-b7c9-a7b4a4513cd9.png?resizew=391)
(1)求证:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7da3da97563be692dacb72023fd36129.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5910e8c06fa225a87e75a0ca34f07cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c818110255bdad691f61be6461a6fd73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098a3e7d1f1890863b7483a98b618119.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb7383ab3dc2ae9dce9b6ff0f8c4fb26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/11/9dd264e9-8795-480e-b7c9-a7b4a4513cd9.png?resizew=391)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/433c893a6102aaf917b8c3ff623745c2.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be2e2c0d4ac2bd79f6cea7a9b1a50662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fbbe7f48676298f2ee0cb1901992eaf.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,三棱柱
中,各棱长均相等,
,
,
分别为棱
,
,
的中点.
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654848568573952/1655778777300992/STEM/4a5c5209c63e47cdbbc173754e84f6e7.png?resizew=226)
(Ⅰ)证明:
平面
;
(Ⅱ)若三棱柱
为直棱柱,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/2017/3/30/1654848568573952/1655778777300992/STEM/4a5c5209c63e47cdbbc173754e84f6e7.png?resizew=226)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
(Ⅱ)若三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在四棱锥
中,平面
平面
,底面
为菱形,
,
是
的中点.
平面
.
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.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/05740f0c6071846227dc0ec177ad15e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afc7eef759df95a3ed7247d1b282f506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc9f783884705e6092fd35fd9222dae1.png)
您最近一年使用:0次
解答题-问答题
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适中
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【推荐2】正方形
的边长为2,
,
分别为边
,
的中点,
为线段
的中点,如图将正方形沿
折起,设
(
).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/b6d2863e-b07d-40af-87f0-df9856f3461b.png?resizew=191)
(1)直线
与由
,
,
三点所确定平面的交点为
,试确定点
的位置,并证明直线
平面
;
(2)若二面角
的余弦值的绝对值为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b149b02b7dfca7d1a511603ef79600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0917d846965359153058d56498f076bb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/b6d2863e-b07d-40af-87f0-df9856f3461b.png?resizew=191)
(1)直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1e8fce8b2c9d2d3b7fbc0ad0a617bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3935b5b39d54577a64aa280accbb5fee.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc6254fdf3ab25161b65f5c86c6c42d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0e23ab2a5db0d58b522f1e2699bfe60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
您最近一年使用:0次
解答题-作图题
|
适中
(0.65)
名校
【推荐3】
是边长为2的正三角形,P在平面上满足
,将
沿AC翻折,使点P到达
的位置,若平面
平面ABC,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/5/922e2631-442f-4c5e-9e86-28355cba488f.png?resizew=265)
(1)作平面
,使得
,且
,说明作图方法并证明;
(2)点M满足
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da35b5c539d7ac40137eb9f665571f53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147de24f071e316b68fd2e78e3c84545.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee6765a83140d745a6de4c85d9b6b50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9b0255047b563fb5828ba05ea63049a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1095457a1433e68cc63eebe0d0c218c2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/5/922e2631-442f-4c5e-9e86-28355cba488f.png?resizew=265)
(1)作平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88edffc97ba3b98d5e8c9e55016fa018.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcc1653fc8447569107a484816b27a7.png)
(2)点M满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9da932bf1051907c0433c169fef04b14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d4d818cdb553e6e71cf91dac1089257.png)
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