在正四棱锥
中,O为顶点在底面内的射影,P为侧棱SD的中点,且
.求直线BC与平面PAC所成的角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab1e7a9b8a0c101a33bf3e5bb96c1117.png)
更新时间:2021-02-07 16:27:51
|
【知识点】 线面角的向量求法
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】如图1所示,在平行四边形
中,
,
,将
沿
折起,使得二面角
的大小为
,如图2所示,点
为棱
的中点,点
为棱
上一动点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/27/569a2295-8d16-414e-8b51-46bac0a8002b.png?resizew=412)
(1)证明:
;
(2)若四棱锥
的体积为
,求直线
与平面
所成角的正弦值的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4864c21e9664fa9111ede6425b09563a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c583493109d50c9e4634c05e9042a9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbc4c58d7bdd6ecebf94c0d6add63ba6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f479b251fdb01bae6d16abb7f2d694a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/27/569a2295-8d16-414e-8b51-46bac0a8002b.png?resizew=412)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4737454d911a7d41ce1a8521631a6c59.png)
(2)若四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.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2】如图,在四棱锥
中,点
是
的中点,点
在棱
上,
,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/27/be4fb0ef-4d89-4df8-a749-60f35ce5c773.png?resizew=149)
(1)证明:平面
平面
;
(2)若点
是
的中点,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.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/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8254b52b379a420c17d38334940b073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5729dd997ea7e8cb4cef8b7165b36e00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea3e27f6e6d1592408508cc9fd14d480.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/27/be4fb0ef-4d89-4df8-a749-60f35ce5c773.png?resizew=149)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3599e2d14048d66477e736223dd591d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)若点
![](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/63a253c7fdf589ee3dece13d5b5b5732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6261790c66cc71ee3898afabad0c09f4.png)
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,已知正方体
的棱长为
分别是
的中点,
是
上一点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/7/d13caa2e-602a-4bd1-81d1-18b5bc3d932c.png?resizew=174)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89952953873ddf693370dedd910d86be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79c4bf3d636b63efd9cbc1b0de58f8be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/520e213ecdc97d202c37ca8356a979fc.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/7/d13caa2e-602a-4bd1-81d1-18b5bc3d932c.png?resizew=174)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c08b9a48b3f89132f323efcdb014430.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/becf2941e15d668d93ea6ed980afd0ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c08b9a48b3f89132f323efcdb014430.png)
您最近一年使用:0次