已知三棱锥P-ABC(如图一)的平面展开图(如图二)中,四边形ABCD为边长等于
的正方形,
和
均为正三角形,在三棱锥P-ABC中:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/9ba59c35-1bef-4eec-a2c6-58422671cc87.png?resizew=341)
(1)证明:平面
平面ABC;
(2)若点M在棱PA上运动,当直线BM与平面PAC所成的角最大时,求直线MA与平面MBC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/9ba59c35-1bef-4eec-a2c6-58422671cc87.png?resizew=341)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
(2)若点M在棱PA上运动,当直线BM与平面PAC所成的角最大时,求直线MA与平面MBC所成角的正弦值.
更新时间:2020-03-24 21:00:38
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】在四棱柱
中,四边形
是平行四边形,
平面
,
,
,
为
中点.
![](https://img.xkw.com/dksih/QBM/2017/5/7/1682053802385408/1683332464091136/STEM/53db5230-3c5a-4770-a80f-1b2a2f613296.png)
(1)求证:平面
平面
;
(2)求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ecf072589c0f901d92f6bda111d841.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1b0fc0bfca09c292e157cbb02835342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://img.xkw.com/dksih/QBM/2017/5/7/1682053802385408/1683332464091136/STEM/53db5230-3c5a-4770-a80f-1b2a2f613296.png)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba0fbd88fdb064072eedd136e9cb41ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfb3f0b5d8bf98eeff66f43b7dcbb4be.png)
(2)求多面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed3318ae44a33a06039c1b2bb7c9bbc5.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图,四边形
为正方形,
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/042335d01aa2e7f6b6ca58569c7585b9.png)
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/4/60a235fe-996a-4e6b-9346-b0fe7be64b75.png?resizew=160)
(1)证明:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69b7af35a4b337ee57859c186abc0c2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/042335d01aa2e7f6b6ca58569c7585b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aae36b5ad88943a96826ad0a5ed7f82a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/4/60a235fe-996a-4e6b-9346-b0fe7be64b75.png?resizew=160)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4a46fbde58e12b1edc038ae9e921722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ac66de8543430fd51e7c18042e626dd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2def0d393ca995cfe6e2deb25fb35d3.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,
是边长为2的正方形,
是矩形,且二面角
是直二面角,
,G是EF的中点.
![](https://img.xkw.com/dksih/QBM/2022/4/7/2953036310659072/2953893680889856/STEM/c584bfde96ad41e58d8cda3b21e43fd3.png?resizew=157)
(1)求证:平面
平面
;
(2)求GB与平面
所成角正弦值的大小;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f22eea13efafb003e7b08a6f0bc0f2f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0cee0f36dc452e58086832c0152b641.png)
![](https://img.xkw.com/dksih/QBM/2022/4/7/2953036310659072/2953893680889856/STEM/c584bfde96ad41e58d8cda3b21e43fd3.png?resizew=157)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1978708de056a73d9212bb7849410b56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c4cf25fb8f21502066f97d9c4c66843.png)
(2)求GB与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15e3189ee19551c4fb5dfe8bd1a73329.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,在五面体ABCDEF中,底面ABCD是矩形,△BCF是边长为2的等边三角形,平面
平面ABCD,
,二面角
的大小是
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/6/a399cf68-2f49-4df2-bd3c-8774b70b1e61.png?resizew=215)
(1)求证:直线
平面ABCD;
(2)求直线AE与平面CDEF所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd2d28f1e7a6b17401c19c34beddcbe0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ab99bc7019349302a8eec686cea5ff6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/213d25b5ade550ec6afd3536e9eb5d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037fb348109dc2063a268b10eb925a57.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/6/a399cf68-2f49-4df2-bd3c-8774b70b1e61.png?resizew=215)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
(2)求直线AE与平面CDEF所成角的正弦值.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在三棱锥
中,
是边长为2的等边三角形,
,直线
与平面
所成的角为30°.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/6/07d203e6-acda-4a31-b3d1-d7723e5a8ed3.png?resizew=169)
(1)证明:
平面
.
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89c416b5f18fbb0b7f79e8a5702acd13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5651786f20fba106499b53b7e142db29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/6/07d203e6-acda-4a31-b3d1-d7723e5a8ed3.png?resizew=169)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa3c61d6c19e187b4b824b6f5610cdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4734735213b599a9915e1ed91a5d8ce4.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,已知棱长为l的正方体
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/7/5c865812-a15b-4ebf-a129-accf68226f50.png?resizew=175)
(1)在侧棱
上是否存在一个点P,使得直线AP与平面
所成角的正切值为
.
(2)若P是侧棱
上一动点,在线段
上是否存在一个定点Q,使得
在平面
上的射影垂直于AP?证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/7/5c865812-a15b-4ebf-a129-accf68226f50.png?resizew=175)
(1)在侧棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bf9ef324f1289e205e29fed105c38e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8af2fdf1944afebb51cb6a5e6c74aadd.png)
(2)若P是侧棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d41164f8a9f6fe32a9364f18f168dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bf21323743db36f3a2ea9ce620e9bc3.png)
您最近一年使用:0次