如图,在三棱锥D-ABC中,
,
,M,N分别是线段AD,BD的中点,
,
,
,二面角
的大小为60°.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/3/91788f67-dbce-49bb-ac2f-4ae9d11bee0e.png?resizew=155)
(1)证明:△ABC为直角三角形;
(2)求直线BM和平面MNC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8915e8e775538d41debf1933102c6b86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bd6a2b112facda441f4e34bf5c145fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b810bf15975ccb16c38034b41bb46b0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1719410d21e3de1242366ce2965e838c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/107b87854ea594f77a40b25becd36020.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/3/91788f67-dbce-49bb-ac2f-4ae9d11bee0e.png?resizew=155)
(1)证明:△ABC为直角三角形;
(2)求直线BM和平面MNC所成角的正弦值.
更新时间:2023-04-27 11:23:42
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在四棱柱
中,底面
是等腰梯形,
,顶点
在底面
内的射影恰为点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/c1a649e0-9ab0-43cf-8f82-d73cd787bb1f.png?resizew=225)
(1)求证:
平面
;
(2)若直线
与底面
所成的角为
,求平面
与平面
所成锐二面角的余弦值.
![](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/018330d4591b1e90cd8205a17d79d8b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/c1a649e0-9ab0-43cf-8f82-d73cd787bb1f.png?resizew=225)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96872cd6cd581ae8a861c7032e0257b4.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af9955b5aebb73cd84447e8541f901ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/679748eab882a6be0fefd2cc300349a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96872cd6cd581ae8a861c7032e0257b4.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】 如图1,在
中,
°,
,
,D,E分别是AC,AB上的点,且
,
,将
沿DE折起到
的位置,使
,如图2.
![](https://img.xkw.com/dksih/QBM/2015/1/7/1571956258553856/1571956264460288/STEM/e9fd9b198a7e49259cec9e3895d22d1a.png?resizew=350)
(1)求证:
平面
;
(2)若M是
的中点,求
与平面
所成角的大小;
(3)点F是线段BE的靠近点E的三等分点,点P是线段
上的点,直线l过点B且垂直于平面
,求点P到直线l的距离的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8807117d0d649419fdda04c531cdc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20d9a22edaf816e0975bd82f61de9df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95a078495ba47076ccaa28b46f765d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/377b5f7197e5bd1afeea4d931307956a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa2a83fed9bf4cb09d84a980452e346.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2fef4031c10abc18c8747af6b9a8a.png)
![](https://img.xkw.com/dksih/QBM/2015/1/7/1571956258553856/1571956264460288/STEM/e9fd9b198a7e49259cec9e3895d22d1a.png?resizew=350)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d26d8a9d64ad3c8cba28840b41ed7837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
(2)若M是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
(3)点F是线段BE的靠近点E的三等分点,点P是线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f348ed8a1690d3ed02aa64459ca50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图所示的几何体是一个半圆柱和一个三棱锥的组合体.
是半圆柱的母线,
分别是底面直径BC和
的中点,
是半圆
上一动点,
是半圆
上的动点,
是圆柱的母线,延长
至
点使得
为
的中点,连接
,
构成三棱锥
.
;
(2)当三棱锥
的体积最大时,求平面
与平面
的夹角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ebf67d880172b27fefacc3c5b808eae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4d6cde991efd85f03f8801e745127a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683e17492ad37eeab880209057cb0feb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0ff310aabd2282b539537ebed3f788.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30513ea48bc1ef3ae78adac83d894f14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4d260c4df7b0dc180af6980d21f3371.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf5ae8d145c5ce43e4cfc95fe6f563ed.png)
(2)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e367b683581c7cbe018078168f69efc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6b36a70bc52a720ba8750aee4924307.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图(1)所示,AD是△BCD中BC边上的高线,且AB=2AD=2AC,将△ACD沿AD翻折,使得平面ACD⊥平面ABD,如图(2).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/cfc8d761-8a09-42af-bfff-35f8290ef6dd.png?resizew=332)
(1)求证:AB⊥CD;
(2)图(2)中,E是BD上一点,连接AE、CE,当AE与底面ABC所成角的正切值为
时,求直线AE与平面BCE所成角的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/cfc8d761-8a09-42af-bfff-35f8290ef6dd.png?resizew=332)
(1)求证:AB⊥CD;
(2)图(2)中,E是BD上一点,连接AE、CE,当AE与底面ABC所成角的正切值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.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,四边形
是菱形,
底面
,
,
与
在平面
的同侧且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/cb7dbb20-8c74-4da7-81a1-ed97e7743e5d.png?resizew=168)
(1)证明:
平面
;
(2)若
与平面
所成角的正切值为2,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/ab854f94328c61d47f8b0d5437ed5889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3591d69ccb647aad652bb90b39a8752.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/cb7dbb20-8c74-4da7-81a1-ed97e7743e5d.png?resizew=168)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f306ff6d237cd9d847aa109acf9333d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9068f29d671d76d1e95ba3a4eaff5b96.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7296b8171cf078044e219c285b53f80a.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图,三棱柱
中,侧面
底面
,
,
,
,点
是棱
的中点,
,
.
;
(2)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/85a2e10a5aebe40a9018d5ee3ade7af8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4639a9dc0bc99101cbde59fef04b4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1f4f255d191786f7d330d278868c2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25a0b476b289ac25846a989a90059376.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cb61907b2cc3430c4100c8f04cd15a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bffd657e48b15b9b54a55817e2c26b22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1de5964353beb55c5058b2a431eecaf.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1803d62a881048bd8ac156c7e5d284df.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,
平面ABCD,
,
,
,
,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3362a45b72536c714c5107b0ae94f1c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/8e62846c-9341-4fe6-b466-6020cd64d119.png?resizew=176)
(1)求直线CE与平面BDE所成角的正弦值;
(2)求平面BDE与平面BDF的夹角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f555fb7ea6e77a6e0fe38586a3992d50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9060f03b9ee41d70d135b1e1a8902ce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27db558e8db4c957654c8e5cecd2d2dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24aa9c45aead7671df2572da4456617a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3362a45b72536c714c5107b0ae94f1c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/8e62846c-9341-4fe6-b466-6020cd64d119.png?resizew=176)
(1)求直线CE与平面BDE所成角的正弦值;
(2)求平面BDE与平面BDF的夹角.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】已知平行四边形
中,
,点
在
上,且满足
,将
沿
折起至
的位置,得到四棱锥
.
![](https://img.xkw.com/dksih/QBM/2021/5/8/2716531541680128/2744334152720384/STEM/b264e1f6-39a2-4138-8cd6-3815e32a61ba.png?resizew=488)
(1)求证:平面
平面
;
(2)若二面角
的大小为
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/953f11eb95bfc036d85b472f81c6fb4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e5dc410a2c45d2e3518500b85d10d99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b6accdd9b317c922d335e44911df357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e98920101c174b991d7a8481707ab88.png)
![](https://img.xkw.com/dksih/QBM/2021/5/8/2716531541680128/2744334152720384/STEM/b264e1f6-39a2-4138-8cd6-3815e32a61ba.png?resizew=488)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ac48b9ac8efbf41d6ab5242d247bd89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3f18f6c39be0fc537fc3ae491107843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/231b861d6d1f1d0b9f52b041cb40eb62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次