如图,在长方体
中,底面
是边长为2的正方形,
,
,
分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/16/efd708db-d28e-4896-b142-e6c2538de740.png?resizew=155)
(1)证明:
∥平面
;
(2)求平面
与平面
夹角的余弦值.
![](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/e8d927585a17c2e98ef7d5a9589a26ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe734023d4e70010a6b2cc3267cb86e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/16/efd708db-d28e-4896-b142-e6c2538de740.png?resizew=155)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c52091eb745de866044477641a7c55f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc78a86b12ba0b4553135a3a635fc418.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70db40c42655327adee01caedfc9d50c.png)
更新时间:2022-11-13 16:48:39
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在直角梯形ABCD中,AB∥CD,AB⊥AD,且AB=AD=
=1.现以AD为一边向梯形外作正方形ADEF,然后沿边AD将正方形ADEF折叠,使ED⊥DC,M为ED的中点,如图2.
![](https://img.xkw.com/dksih/QBM/2022/7/7/3017582677557248/3018326813229056/STEM/bf66506b301e466db97a32f48358a04e.png?resizew=410)
(1)求证:AM∥平面BEC;
(2)求证:BC⊥平面BDE;
(3)求点D到平面BEC的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b840be5852709e18ea985954545e78d.png)
![](https://img.xkw.com/dksih/QBM/2022/7/7/3017582677557248/3018326813229056/STEM/bf66506b301e466db97a32f48358a04e.png?resizew=410)
图1 图2
(1)求证:AM∥平面BEC;
(2)求证:BC⊥平面BDE;
(3)求点D到平面BEC的距离.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】在如图所示的几何体中,四边形ABCD为正方形,
平面ABCD,
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/12/24/2879338726187008/2885782982721536/STEM/f57182152d04495d9422f7417512ee73.png?resizew=144)
(1)求证:
平面PAD;
(2)求直线PD与平面PCE所成角的正弦值;
(3)在棱AB上是否存在一点F,使得平面EPC和平面FPC所成角为60°?如果存在,确定点F的位置;如果不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18e2605cd905f703a8fda77540347ad9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60634341a9603e24b2bbc6960abe3d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82465b63174087aeba7788ed984583d2.png)
![](https://img.xkw.com/dksih/QBM/2021/12/24/2879338726187008/2885782982721536/STEM/f57182152d04495d9422f7417512ee73.png?resizew=144)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a20ea69475dcf57a5ff18c13eceaaa.png)
(2)求直线PD与平面PCE所成角的正弦值;
(3)在棱AB上是否存在一点F,使得平面EPC和平面FPC所成角为60°?如果存在,确定点F的位置;如果不存在,说明理由.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图,四边形
是正方形,
平面
,
,
,F,G,H分别为BP,BE,PC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/18/c9bc57f8-b7a8-4ad0-aa4b-7fe8bd330f50.png?resizew=145)
(1)求证:
平面
;
(2)求平面
与平面
夹角的大小;
(3)求直线CE与平面PBC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7544991965a1b17affc840edbe27d21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f45ea9d4410e9926c592fa0a9dfac97.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/18/c9bc57f8-b7a8-4ad0-aa4b-7fe8bd330f50.png?resizew=145)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f60d66204e1abc17bd01749f187f8050.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1828e73ec5e00f95aa11ff74c703a5c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(3)求直线CE与平面PBC所成角的正弦值.
您最近一年使用:0次
解答题
|
适中
(0.65)
名校
【推荐1】如图,等腰直角
与梯形
所在的平面垂直,且
,
,
,
,
,
为
中点.
(1)证明:
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4020b47658346639e42836fea8e672c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b6a63b5590530bdc5a254489cf2b212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99d2b7b1c72487fdb8b1089a6317d6c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed9727fd50173b6c5b15e13038ec3aea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13efd2b5236b93d982847ecf97efbf12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/252053b853152bd294a8315debd00b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c0a8dae112675431078b896e724c3cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf12905647aeeded72bbca21a63f319.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b8890d630c88be68fba6044e2bce720.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/31/a7706209-2614-4455-a54f-62ebe87426aa.png?resizew=235)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,在直三棱柱
中,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/3b933154-ff56-45c0-aee0-912e32fcb2a2.png?resizew=171)
(1)证明:
平面
.
(2)若
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97724e0e7ea9894c189872c3c33bdb3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/3b933154-ff56-45c0-aee0-912e32fcb2a2.png?resizew=171)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6d06903252260d31d1a9cdeb735b089.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfb08f6a798dc293f3d8de281190f65e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c9f93a58248231c2a09380855e46782.png)
您最近一年使用:0次