如图,在四棱锥
中,底面ABCD是直角梯形,
,
∥
,侧棱
平面ABCD,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/059fed80-c31f-496c-aed4-72eee723fb2f.png?resizew=155)
(1)求证:平面
平面
;
(2)求平面
与平面
所成二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f47aa404cffdc69dbe212fb61f32e244.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/059fed80-c31f-496c-aed4-72eee723fb2f.png?resizew=155)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b6e6192cf24ada791c26c2d6d434069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ef796b46e68fe77b117ff0483d2370c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
更新时间:2020-03-04 22:23:39
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图所示,在直三棱柱
中,
,
平面
,D为AC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/9132be8a-cfd6-48e1-8ba1-f9cfc446eb08.png?resizew=166)
(1)求证:
平面
;
(2)求证:
平面
;
(3)设E是
上一点,试确定E的位置使平面
平面BDE,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60a9e3a0abf0df191f89169468f95bbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d1d2e0f281222a5f289ea4008370aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/9132be8a-cfd6-48e1-8ba1-f9cfc446eb08.png?resizew=166)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/504a36c231b8e80724d01649e7c0944f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a59d296654aa17749f8300ae1d1da0e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
(3)设E是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba0fbd88fdb064072eedd136e9cb41ff.png)
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解答题-证明题
|
适中
(0.65)
【推荐2】如图,在平行四边形
中,
,将
沿对角线
折起,折后的点
变为
,且
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cb16a791ce234a13ec793867b64724b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00135791b38a81a8db0c228bfddbdc62.png)
(Ⅰ)求证:平面平面
;
(Ⅱ)求异面直线与
所成角的余弦值;
(Ⅲ)E为线段上的一个动点,当线段
的长为多少时,
与平面
所成的角正弦值为
?
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,在四棱锥
中,平面
平面
,底面
为平行四边形,
,
.
![](https://img.xkw.com/dksih/QBM/2018/5/2/1936784119185408/1937176798920704/STEM/f3de4a953365407a8b7f94572208b454.png?resizew=239)
(1)求
的长;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed5f0cfc1049f84a04c81bd213afb8d9.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/2568205253af3d51e1c50c8d9fa81aa6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a0ecba7e1969a265ff75bcb17ed9d2e.png)
![](https://img.xkw.com/dksih/QBM/2018/5/2/1936784119185408/1937176798920704/STEM/f3de4a953365407a8b7f94572208b454.png?resizew=239)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51e231505648333857565accb0c3c898.png)
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【推荐2】如图,在四棱锥P-ABCD中,底面ABCD是边长为2的正方形,
,
,二面角
为60°,E为PD的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/d6d7c8ba-1611-42a7-a3ce-384c9a3a1c82.png?resizew=210)
(1)证明:
平面PAD.
(2)求平面ADE与平面ABE所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19d8537bfc5cf701c841636d24aef5be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba4c15fb8fc3239d45bd4e7d8971f58e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c911b404bbb8f8d5f1470585fa31ad97.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/d6d7c8ba-1611-42a7-a3ce-384c9a3a1c82.png?resizew=210)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
(2)求平面ADE与平面ABE所成锐二面角的余弦值.
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