如图,在四棱锥
中,平面
平面BCDE,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/30/5cf54a92-71f2-4e18-a39e-21016bd42a20.png?resizew=126)
求证:
平面ABC;
求平面ABE与平面ADC所成二面角大小的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5950b2be8b3a4cef62580f73f7e2f778.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99bfa2ca4e398c8ab0f97f47add3754f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/265ad748834e159aaeeb9e4e7ccc294b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc219dbd7f28fc44d8dab340ff4b5c58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50b77d1a22977ce5f43d36e40b648bd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef27ae2e2bd091fa0879d0ea96c6d1e9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/30/5cf54a92-71f2-4e18-a39e-21016bd42a20.png?resizew=126)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4141b26d2c32655003494a91ad6331b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffd244dd270528347a22d8101ac73726.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65863c1abad833b79c303bfca24f535c.png)
2019·新疆·一模 查看更多[2]
更新时间:2019-03-27 08:59:33
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】在五面体
中,
∥
∥
,
,
,
,平面
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/b036d31a-0b90-46a2-b41f-a71a0b5da739.png?resizew=178)
(1)证明:
平面
;
(2)棱
上是否存在一点
,使得二面角
的大小为
?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b66d0c4532b4e7826e61fa718b28153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/def212da83f08df1309c9833521e2a8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5a68a008a22d5a8cea5fe8dcf31e10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/b036d31a-0b90-46a2-b41f-a71a0b5da739.png?resizew=178)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa3254460ecbacecb3e57c5dce227f4.png)
(2)棱
![](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/fe1df39b6ba5161e0ece93b93887e4b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39d7835a3f4516b428b37d99fc789084.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
名校
【推荐2】如图,正三棱柱
中,
,
.点
是
的中点.
(1)求四面体
的体积;
(2)求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/14/614d4b4f-c748-4eab-82de-b840c8b2122b.png?resizew=119)
(1)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b274492c671a0606343ca592acc83099.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b66a5b7813e902306477f91f9f4084cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,四棱锥中
,底面
为直角梯形,
,
,平面
底面
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/ee2f56da-053f-48c4-a16a-90ec702ac2ff.png?resizew=129)
(Ⅰ)判断平面
与平面
是否垂直,并给出证明;
(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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4795ee1f96b430529934e2231b38885d.png)
![](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/62974d34de3a12418d6b700420afd1b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e839ac941e8bf536ff35a12e56c7a400.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/ee2f56da-053f-48c4-a16a-90ec702ac2ff.png?resizew=129)
(Ⅰ)判断平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18120a244d3a1f9c1688bf53eb2ad775.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.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,在平行四边形
中,
,
,
在
上,且
,将
沿
折起到
的位置,使平面
平面
.
![](https://img.xkw.com/dksih/QBM/2021/5/18/2723899487272960/2724426051182592/STEM/35ee57e6-6bb9-4f13-8ae6-f357d1184c79.png?resizew=508)
(1)求证:
.
(2)求二面角
的余弦值的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0041488020a3e19377b18a70fbf82e7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82773737609e65dea3c5c67099f1b10d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63b43490ca09467a4c8cd8cfe91c94e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbe40405cd7bd60d69dd535d6da85c00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90d96357a07048ba79b8c84097d359d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
![](https://img.xkw.com/dksih/QBM/2021/5/18/2723899487272960/2724426051182592/STEM/35ee57e6-6bb9-4f13-8ae6-f357d1184c79.png?resizew=508)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f45265eaed2ba5fc08f6a112a02cd2.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
您最近一年使用:0次