如下图所示,在多面体
中,
是边长为2的等边三角形,
,
,点
是
中点,平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/6dae8325-cf62-4a92-ace9-958afa1056e2.png?resizew=177)
(1)求证:
平面
;
(2)
是直线
上的一点,若二面角
为直二面角,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba5c70f4ec3913a79c8f9b35ef5e9084.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8657dae5b24411e0eb91ee5b4f72a1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/014482a0eb1051754b34dd440225deed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/6dae8325-cf62-4a92-ace9-958afa1056e2.png?resizew=177)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063510e3c1fb6a7ccc3b8e3e3c7d660e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eef42c512efb558f81b1d18cc9a49704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
更新时间:2021-12-05 11:47:15
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在三棱柱ABC-A1B1C1中,四边形B1BCC1是菱形,∠B1BC=60°,AB⊥BC,AB⊥BB1,D为棱AC的中点,E为棱BC的中点.
![](https://img.xkw.com/dksih/QBM/2021/6/8/2738591493709824/2761481260089344/STEM/c958c3d8-5d43-46fb-a081-a6d9e64e3e45.png?resizew=283)
(1)求证:AB1∥平面BC1D;
(2)若AB=BC=2,求点B到平面AB1E的距离.
![](https://img.xkw.com/dksih/QBM/2021/6/8/2738591493709824/2761481260089344/STEM/c958c3d8-5d43-46fb-a081-a6d9e64e3e45.png?resizew=283)
(1)求证:AB1∥平面BC1D;
(2)若AB=BC=2,求点B到平面AB1E的距离.
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名校
【推荐2】如图,在梯形
中,
,
,
,将
沿
折起,形成四棱锥
,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/daab8a85-c32c-4742-8dfa-9e3f52e79c39.png?resizew=367)
(1)若点
为
的中点,求证:
平面
;
(2)在四棱锥
中,
,求面
与面
所成二面角(锐角)的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fe54ef71bf348f6c21a853aae5545f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4151e948feebdf7b91fbe739feafa9bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5164a3cc47e266446d49127e2ef10c37.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/daab8a85-c32c-4742-8dfa-9e3f52e79c39.png?resizew=367)
(1)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e0684e0b09b04661c602437982c0397.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(2)在四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5164a3cc47e266446d49127e2ef10c37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
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解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图1,在五边形
中,连接对角线
,
,
,
,将三角形
沿
折起,连接
,得四棱锥
(如图2),且
为
的中点,
为
的中点,点
在线段
上.
(1)求证:平面
平面
;
(2)若平面
和平面
的夹角的余弦值为
,求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba5c70f4ec3913a79c8f9b35ef5e9084.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a0e5697eca3f5205cb7b343648240bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/250dc8bc2157eab517d549ca8ee561f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/829a1a887ceba13dd8551b1e3604bf6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/144b759bf5a81cd63839eddf599c788d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/7/bd9d7899-0fc2-4bb7-8503-fccad153d582.png?resizew=280)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1885efcff0b903e314057dd153578600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b0723074da804de8b4c2b9a51bbe276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c4c865445dda4a59b6d5cb18fd74404.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
【推荐2】如图,在正四棱柱ABCD﹣A1B1C1D1中,AB=1,AA1=t,建立如图所示的空间直角坐标系O—xyz.
(1)若t=1,求异面直线AC1与A1B所成角的大小;
(2)若t=5,求直线AC1与平面A1BD所成角的正弦值;
(3)若二面角A1—BD—C的大小为120°,求实数t的值.
(1)若t=1,求异面直线AC1与A1B所成角的大小;
(2)若t=5,求直线AC1与平面A1BD所成角的正弦值;
(3)若二面角A1—BD—C的大小为120°,求实数t的值.
![](https://img.xkw.com/dksih/QBM/2018/6/27/1976377785122816/null/STEM/ef607c5e15d94c9c9c94ab7635e2955d.png?resizew=136)
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