如图,在直四棱柱
中,底面
为菱形,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/34c98b1d-78f5-48f5-b4c8-468fbb2cc944.png?resizew=169)
(1)证明:
平面
;
(2)若
,
,求二面角
的正弦值.
![](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/f7dbf31dfd36aa456a63bafea8bc1985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/34c98b1d-78f5-48f5-b4c8-468fbb2cc944.png?resizew=169)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7767d492158189b23af332a8016ed37d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebb05874eb3353d754af24c9974273e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d927585a17c2e98ef7d5a9589a26ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d036e80482a268218cc2cbe553910c1.png)
更新时间:2020-05-30 22:02:52
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图:在四棱锥
中,底面
是菱形,
,
,点
,
分别是线段
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/f2d5b0a2-982d-4c26-9db7-769ad78c0a38.png?resizew=163)
(1)求证:
平面
;
(2)若平面
平面
,求三棱锥
的体积.
![](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/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/931bbffda5e872703c9947eccc47ede2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/f2d5b0a2-982d-4c26-9db7-769ad78c0a38.png?resizew=163)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f064cf045ca7a0e0f09e19b3f44759da.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dace6f4bca87f775ee8c48858695ad9b.png)
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|
适中
(0.65)
【推荐2】已知二面角
的大小为
,且
面
,
的面积为5,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02451b1caf05bb6835e580b32ee5f09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af9955b5aebb73cd84447e8541f901ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/060944099caabb1d9ebbffd1b18b2287.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4d781525777c7b5284dffc70b2a28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a855335176fc36a15017f50a8561348.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f8c0c8a16d9e56d7db6a9d8657faf6.png)
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名校
【推荐3】等边三角形
的边长为3,点
、
分别是边
、
上的点,且满足
(如图1).将
沿
折起到
的位置,使二面角
成直二面角,连结
、
(如图2).
![](https://img.xkw.com/dksih/QBM/2020/8/11/2525782809157632/2540246050078720/STEM/f2fa973ea6cd479e86d1c4f9dd6dc2cc.png?resizew=359)
(1)求证:
平面
;
(2)在线段
上是否存在点
,使直线
与平面
所成的角为
?若存在,求出
的长,若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e3cc1d8626c39729dc64691e4a7d00d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa2a83fed9bf4cb09d84a980452e346.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/628d6fc46c651e0c783b81a123a7b229.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://img.xkw.com/dksih/QBM/2020/8/11/2525782809157632/2540246050078720/STEM/f2fa973ea6cd479e86d1c4f9dd6dc2cc.png?resizew=359)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4890e58791814622b87c4d60ea971f54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65c42bce098904b241986bb91c65ab33.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/800c5e266b4ad8462a46970f0a232d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
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【推荐1】如图,已知在长方体ABCDA1B1C1D1中,AD=A1A=
AB=2,点E是棱AB上一点,且
λ.
![](https://img.xkw.com/dksih/QBM/2019/5/6/2197648947609600/2199087646801920/STEM/437a9f367111412ca3ed8bb6565a60dc.png?resizew=143)
(1)证明:D1E⊥A1D;
(2)若二面角
的余弦值为
,求CE与平面D1ED所成的角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1402adb9ccc8f35485e74845973b084.png)
![](https://img.xkw.com/dksih/QBM/2019/5/6/2197648947609600/2199087646801920/STEM/437a9f367111412ca3ed8bb6565a60dc.png?resizew=143)
(1)证明:D1E⊥A1D;
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35988677892d6ffdf4773f7a861f26a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1174142f3bba761585b6bc2653009b36.png)
您最近一年使用:0次
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解题方法
【推荐2】如图,在四棱锥
中,四边形ABCD为矩形,平面
平面ABCD,点O在线段CD上,OB与AC交于点E,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/30/eabbd4d7-519f-4f5a-9e6d-9e72e5655d7c.png?resizew=163)
(1)求证:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70834818750d0454474ac7c357cd287.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bac2291f7339309ce8a2255a8da6eb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/feedf3c1dee6e7befebf368c092ccd0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d4746df85049d1651d3f6c30212a7a9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/30/eabbd4d7-519f-4f5a-9e6d-9e72e5655d7c.png?resizew=163)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccbd1316b9d1f0c1e71fd078deec61f6.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5285e65d622e6fd61f148375c56a6a3e.png)
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【推荐3】如图,三棱柱
中,侧面
为菱形,
.
![](https://img.xkw.com/dksih/QBM/2020/4/27/2450771680542720/2452875684741120/STEM/b99923e5707d4d10ae7c27d7e043da1a.png?resizew=197)
(1)证明:
;
(2)若
,
,
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00ee347187fbbfe9e8a6faf286795d79.png)
![](https://img.xkw.com/dksih/QBM/2020/4/27/2450771680542720/2452875684741120/STEM/b99923e5707d4d10ae7c27d7e043da1a.png?resizew=197)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7870cee007535b979d35bc7feab75616.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96dcc9419f5a85ebd21211e8eef03fc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f2e238b2757353026133bbe495645e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69418f38ada198be25a69cb651e33e04.png)
您最近一年使用:0次