如图,四棱锥
中,底面
为平行四边形,
,
,
.
![](https://img.xkw.com/dksih/QBM/2022/1/21/2899229575905280/2912120870322176/STEM/21ce915db4f341da87dbcf2d2c5a8421.png?resizew=252)
(1)证明:
;
(2)若
为等边三角形,求二面角
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/0f7aca3e85004242ba1821998f59ee05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8817a5a7ea0e96f7c3229c5a06b70919.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0ce06dbe9e1177468781ba4aff85ffc.png)
![](https://img.xkw.com/dksih/QBM/2022/1/21/2899229575905280/2912120870322176/STEM/21ce915db4f341da87dbcf2d2c5a8421.png?resizew=252)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdfa54114f04a75b8c96165b3718ed7f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36aae82d53f2a35d2f95f467bd5b76cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02535e1a690ca111ca7a395a1bf48080.png)
更新时间:2022-02-08 19:07:59
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】如图,正三棱柱
中,E,F分别是棱
,
上的点,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
平面
,且M是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/901e5fec-c720-4e26-9d3f-ca35bf161bc3.jpg?resizew=148)
(1)证明:平面
平面
;
(2)若
,求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/901e5fec-c720-4e26-9d3f-ca35bf161bc3.jpg?resizew=148)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e51838e395dfc9d9ef597d9e01f46272.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d557872d3299577be8c5872ba1ae5b59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5f5b538bcfb898fcc9d3a2dd8a1b080.png)
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【推荐2】如图,AB是圆O的直径,
圆O所在的平面,C为圆周上一点,D为线段PC的中点,
,
.
![](https://img.xkw.com/dksih/QBM/2022/1/17/2896502953730048/2897116802908160/STEM/a475c4a9-e78c-4fef-b232-d10c826b234d.png?resizew=207)
(1)证明:平面
平面PBC.
(2)若
,求三棱锥B-ACD的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ca0b614cdcebac47b434db4aa75b518.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ff7ad82b0938145af6a5ffa2c9596d8.png)
![](https://img.xkw.com/dksih/QBM/2022/1/17/2896502953730048/2897116802908160/STEM/a475c4a9-e78c-4fef-b232-d10c826b234d.png?resizew=207)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
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解答题-证明题
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【推荐1】如图,在四棱锥
中,平面
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/2/23/2405156568244224/2405443918184448/STEM/48a4b83e0d224b24bd7eb7aad6104cd3.png?resizew=164)
(1)求证:
.
(2)若M为线段
上的一点
,求平面
与平面
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/8dd470cd9dfcde7f7e1762af28bc649c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe9d26aa29b3abf4889d939987d5f091.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c34e05423bb934dc663a73b06af3d873.png)
![](https://img.xkw.com/dksih/QBM/2020/2/23/2405156568244224/2405443918184448/STEM/48a4b83e0d224b24bd7eb7aad6104cd3.png?resizew=164)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90fa715d27ae43ec1e157226bc9dea54.png)
(2)若M为线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a73f0c066cf35b6f53ac80ae1a07a9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c610eab074474dc50696f6c482f7297.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5885ebe4cc091ac2085df704ef9c0bb.png)
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解答题-证明题
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适中
(0.65)
【推荐2】如图,六面体ABCDHEFG中,四边形ABCD为菱形,AE,BF,CG,DH都垂直于平面ABCD.若DA=DH=DB=4,AE=CG=3.
![](https://img.xkw.com/dksih/QBM/2020/8/12/2526429558439936/2527001149685760/STEM/356af7cc-4f0f-4551-aa05-2a479d5db5ac.png)
(1)求证:EG⊥DF;
(2)求BE与平面EFGH所成角的正弦值.
![](https://img.xkw.com/dksih/QBM/2020/8/12/2526429558439936/2527001149685760/STEM/356af7cc-4f0f-4551-aa05-2a479d5db5ac.png)
(1)求证:EG⊥DF;
(2)求BE与平面EFGH所成角的正弦值.
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解答题-问答题
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适中
(0.65)
【推荐3】已知三棱锥
的底面
是边长为2的等边三角形,
平面
,
,点
为线段
上一动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/b7a77917-20e7-476c-b988-057b75662ce3.png?resizew=166)
(1)当点
为
中点时,证明:
;
(2)当平面
与平面
所成二面角为
时,试确定点
的位置.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e93e1661d70eca6d7eb848b667e388e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/b7a77917-20e7-476c-b988-057b75662ce3.png?resizew=166)
(1)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d3f843b83e62bab294988a7ea134a63.png)
(2)当平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3653ada76ba0c8afe9d57c8e7832c6ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
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解题方法
【推荐1】在如图所示的多面体中,
平面
平面
,且
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/0f395a70-88e4-42d9-a4d6-2fdaa44c2ab6.png?resizew=219)
(1)求平面
与平面
所成的锐二面角的余弦值;
(2)在棱
上是否存在一点
,使得直线
与平面
所成的角为
.若存在,指出点
的位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed04b01505bbd8a4ac0bc12e46f23bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49ce9b8e1b049cebd811b399c018b919.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92dbb4a08b5906ee4b6d74fcd9287974.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1df05856faae8670e41719807334d488.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/0f395a70-88e4-42d9-a4d6-2fdaa44c2ab6.png?resizew=219)
(1)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558ce69401f3c97930f00ba0e2aa6647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558ce69401f3c97930f00ba0e2aa6647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
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名校
【推荐2】在三棱锥
中,平面
平面
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/25/75f6049e-eb40-4229-922c-9591f885510e.png?resizew=140)
(1)证明:
;
(2)若
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ceb6d5778a6349ce60f273c1af56b82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f829f73b6c3924d17eb78fa414d34d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af96f607b8d9b0b22a373865d2f6c9e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/25/75f6049e-eb40-4229-922c-9591f885510e.png?resizew=140)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee730f6a2551fb1b582ecf290cfea233.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fa950380fd3c95d0782d09d7ac3ee16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36fb434ccf8340815b6e2cadc74b2f09.png)
您最近一年使用:0次