如图,在四棱锥
中,底面
是边长为1的正方形,
,
,且
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2016/12/3/1573196618448896/1573196624371712/STEM/d2fd1357ff094fa2838063431168b224.png)
(I)求证:
平面
;
(II)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6153163fecdf3f410411048428ccaef5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/774e8da25b05a157aa6f58dd97f6e4ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e739708f43d2823797a29a332014c2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bec03e804f0cea1db5cde2aa185056a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/2016/12/3/1573196618448896/1573196624371712/STEM/d2fd1357ff094fa2838063431168b224.png)
(I)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(II)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
更新时间:2016-12-04 23:24:14
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,在四棱锥
中,
底面
,
是直角梯形,
,
,
,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/2020/12/10/2611322233356288/2613355892342784/STEM/40357f326a4b45028318ad61164bf0b7.png?resizew=265)
(Ⅰ)线段
上是否存在一点
,使得点
,
,
,
共面,存在请证明,不存在请说明理由;
(Ⅱ)若
,求二面角
的余弦值.
![](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/4a0e5697eca3f5205cb7b343648240bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd8e727e4efc22b49649f71ae9c9d84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fd3c2e2199cd4565c05b949bc21fc37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/2020/12/10/2611322233356288/2613355892342784/STEM/40357f326a4b45028318ad61164bf0b7.png?resizew=265)
(Ⅰ)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2899e607479d8d1c47d954ae9ebb7144.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5102c216393e133fa25dba98cd78535.png)
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解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,在正方体
中,
为线段
靠近
的三等分点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/dd76cfba-e8a2-471f-b082-0ebfa17b7ea0.png?resizew=174)
(1)若点
满足
,求证:
平面
;
(2)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/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/dd76cfba-e8a2-471f-b082-0ebfa17b7ea0.png?resizew=174)
(1)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6706f7ae359700c68c80184b2739b78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92a365939377980a322f2a232ca47964.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fed2f706801662432b68797e72647c6e.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fed2f706801662432b68797e72647c6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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解答题-证明题
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适中
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名校
【推荐3】如图,在四棱台
中,
,
,四边形ABCD为平行四边形,点E为棱BC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/18/b55bea8d-bb31-4071-9258-67d80c8068c8.png?resizew=217)
(1)求证:
平面
;
(2)若四边形ABCD为正方形,
平面ABCD,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f54638dd4ebf19815a1333d84e42f927.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/18/b55bea8d-bb31-4071-9258-67d80c8068c8.png?resizew=217)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e44edb46eb17d224e0d9a2667c2e5df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)若四边形ABCD为正方形,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35909b72f6e48a33ae9abb1d63ff91aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdf257663b954b4a9e4fe1edef662c9e.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.64)
【推荐1】如图,已知菱形ACSB中,∠ABS=60°.沿着对角线SA将菱形ACSB折成三棱锥S﹣ABC,且在三棱锥S﹣ABC中,∠BAC=90°,O为BC中点.
![](https://img.xkw.com/dksih/QBM/2016/1/25/1572464722821120/1572464729006080/STEM/2aa3de03a1ca4f87b080fe6ec323b38d.png)
(Ⅰ)证明:SO⊥平面ABC;
(Ⅱ)求平面ASC与平面SCB夹角的余弦值.
![](https://img.xkw.com/dksih/QBM/2016/1/25/1572464722821120/1572464729006080/STEM/2aa3de03a1ca4f87b080fe6ec323b38d.png)
(Ⅰ)证明:SO⊥平面ABC;
(Ⅱ)求平面ASC与平面SCB夹角的余弦值.
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解答题-问答题
|
适中
(0.65)
【推荐2】在梯形
中,
,E是线段
上一点,
,
,
,
,把
沿
折起至
,连接
,
,使得平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/4f3fa390-7153-4f01-8405-25adf9766472.png?resizew=375)
(1)证明:
平面
;
(2)求异面直线
与
所成的角;
(3)求点A到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0094d7f0082284659eda005ef722580d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96b08daf5a6880ff23085d10a8b51823.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbfa1a2af7e38d33634c462300df381f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb048f5765a7187c85e304089baf0eb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/235d1553f6806c1eee3b17b94d23f0f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6bfad3f7e65188bcf7f62ea5acdbf4a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/4f3fa390-7153-4f01-8405-25adf9766472.png?resizew=375)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ae72f5e5891249caa10c43224da89c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ef796b46e68fe77b117ff0483d2370c.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
(3)求点A到平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee789c84b1bf2928dd886ff5da863c97.png)
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