已知四棱锥
中,
,
,侧面
底面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/aa7ebfe0-af9a-4270-9020-be7e18de35e0.png?resizew=160)
(Ⅰ)作出平面
与平面
的交线
,并证明
平面
;
(Ⅱ)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eb4584c3230cff789e35b815a82fbb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34a4dcc2f252baca7d50d97dc5e21288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/30/aa7ebfe0-af9a-4270-9020-be7e18de35e0.png?resizew=160)
(Ⅰ)作出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9df740160690029ac1e730c85f20347.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e867e5c7ef4da37d8985ce82022060e.png)
更新时间:2020-04-23 10:07:10
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,
为圆O的直径,点E、F在圆O上,
,矩形
的边
垂直于圆O所在的平面,且
,
.
(1)求证:
平面
;
(2)设
的中点为M,求证:
平面
;
(3)求三棱锥的体积
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c91baecb97fadd4f8ab49e6effcbc04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a951292add4574c1debd16800674e1e.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/603c7e98deecdba0cf3773757a9b8304.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735056c174e8dd7906257a2a50a962a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280247d7df395bb9ea78c51e67b458d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c93a34cbd4c0dc198b74524c0e05a10.png)
(3)求三棱锥的体积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e70da814a1f069b0a2ab9595ad7430ce.png)
![](https://img.xkw.com/dksih/QBM/2012/2/9/1570727480557568/1570727486062592/STEM/a714eee1-3d26-43fa-ac0c-bc3de3514a92.png?resizew=182)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图所示四棱锥
平面
为线段
上的一点,且
,连接
并延长交
于
.
(Ⅰ)若
为
的中点,求证:平面
平面
;
(Ⅱ)若
,求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af56255206799ad9c5eeae9a87572342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c78350d55a674e91aa28a21f1750cd05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6904f78bb6884bf09adbe32f5df197b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/306767c30931d1ec043ee3d795c17ff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b42410e99c9b13bf2e3b22432e15055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3686a991fb2ba017a6890bc6208e8a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3abf3173133683369785897e67fa84.png)
(Ⅰ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4553a3034f89da311519cd866a0a3cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3218f4e510d1f1534088f919dbf929db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e482b51b3ffa1ad0187f00dbaaa220aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bb7b6f22b3bcaac17c9285d6b3f9800.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed0c1be423ce21fa700b3a50ca338738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3bf1d0dd27d8226f112534e09d3926e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/693024f45a190bf71206c9af6d1a8224.png)
![](https://img.xkw.com/dksih/QBM/2018/3/28/1912011609890816/1912617397510144/STEM/387b4d7d496b4771a750ee7481eee513.png?resizew=155)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】如图所示的几何体中,底面
是平行四边形,
,
,四边形
为矩形,平面
平面
,
,点
是线段
的中点.
(1)求证:
平面
;
(2)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/98e486a1aad96167ff62f6fb5136e0bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4b93d7abcfc4c3df48f03aa969c17f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2a4e3f0349fa83dc2a0b7d798f04843.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0cee0f36dc452e58086832c0152b641.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/4/9ce08b78-ecef-4f07-9208-ceb5c6bac913.png?resizew=159)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd4b93d7abcfc4c3df48f03aa969c17f.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13a1be205bf5955cb569d5eabde0eebb.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,三棱锥
的体积为
,
为
中点,且
的面积为
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/20/f5570fe5-2dc8-4370-8aee-60cd5b9abdac.png?resizew=160)
(1)求顶点
到底面
的距离;
(2)若
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c09b106ad711ff5cd8693ed8400a6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af260e0d98c95d1e092dc4c6d348e3ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90fa715d27ae43ec1e157226bc9dea54.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/20/f5570fe5-2dc8-4370-8aee-60cd5b9abdac.png?resizew=160)
(1)求顶点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ccf63c3731a7351c03fcc98365c6cc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc6f6dfdbe7d39891c35f67e1a95c7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21665d21bbfb04410c78345de1fd15ae.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】已知三棱柱
中,
,
,
平面ABC,E为AB的中点,
为
上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/89d4e246-9203-4f33-92ce-29bd0a25a6ec.png?resizew=144)
(1)求证:
;
(2)当
为
的中点时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa345e314208fcb6b3b29cb8130be32c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/89d4e246-9203-4f33-92ce-29bd0a25a6ec.png?resizew=144)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ccd5c41c921836b50f8e18abfdc5df3.png)
(2)当
![](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/6c2898853a3396f0878af9eac934416d.png)
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