如图,四棱锥
,底面
是正方形,
,
,
,
分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/e12eacc2-7139-40e0-a29b-0dddcb7de54f.png?resizew=174)
(1)求证
;
(2)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/298f423208408bf66383df4f8cbe5e28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/069861e12b842ee7862ce91e870bc606.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/e12eacc2-7139-40e0-a29b-0dddcb7de54f.png?resizew=174)
(1)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a0b29cc24e75be59cbaa5c60a4b4c6e.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/864689852707154e3a9be79f657f16d4.png)
2018·新疆乌鲁木齐·三模 查看更多[6]
更新时间:2018-04-27 17:26:27
|
相似题推荐
【推荐1】如图,四棱锥
的底面是矩形,
底面
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/28/256c95b9-0cb5-4f01-bd3c-0058cc0eb6cf.png?resizew=156)
(1)求证:平面
⊥平面
;
(2)若二面角
为
,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e7b6d04f024ca05cdfacc8ce9137c15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/28/256c95b9-0cb5-4f01-bd3c-0058cc0eb6cf.png?resizew=156)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f615c1e601990cde607f0216f715d57b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64eb31601464364be2baf4aa87404bcd.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
解题方法
【推荐2】如图所示,在等腰三角形ABC中,BA=BC=
,
,在菱形BCDE中,
,AE=
.
![](https://img.xkw.com/dksih/QBM/2019/5/28/2213257240985600/2213568169648128/STEM/c2ef28641105495f85d3ad1955166f0b.png?resizew=158)
(1)求证:平面ABC
平面AEC;
(2)设直线CE与平面ABE所成的角为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392b9e1a179a6676362679354a9e7e51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9593687b8b47481b6c673ae4db5a7839.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/2019/5/28/2213257240985600/2213568169648128/STEM/c2ef28641105495f85d3ad1955166f0b.png?resizew=158)
(1)求证:平面ABC
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
(2)设直线CE与平面ABE所成的角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de7d5ef3a3d9a03be91135fc426d57cc.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
【推荐1】如图所示,正四棱锥
为侧棱
上的点,且
.
(1)求证:
;
(2)求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19a42fd546a43f78f0bc7f50bdb8be0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b2883beed42e46f8f379b02ea3b68b2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/1/5f0c2fc1-6c87-46d0-a978-55824eb6f436.png?resizew=151)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c177e06cc3f703e8ca7be7c491fa2942.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9f1e2b86f4eca37c72011d3dffb0c9.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
【推荐2】如图,平面
平面
,四边形
为正方形,点
在正方形
的外部,且
,
.
![](https://img.xkw.com/dksih/QBM/2021/1/8/2631832881381376/2639670785196032/STEM/8947bc0f-7a50-405f-8995-d5aec2c07a38.png?resizew=271)
(1)证明:
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/e9905abb76186af63eb7e9565d796bce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f13007c6d134c50004c62dc240707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f13007c6d134c50004c62dc240707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b9d54cbbf601f4583659771eb534997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1efa2b0018617bd579875185dafca39a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://img.xkw.com/dksih/QBM/2021/1/8/2631832881381376/2639670785196032/STEM/8947bc0f-7a50-405f-8995-d5aec2c07a38.png?resizew=271)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d27ff0b39832f094ec51e28721d739.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24dc8826770249f3996b8a188c03da92.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24dc8826770249f3996b8a188c03da92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
您最近一年使用:0次