如图所示,四棱锥
的底面是梯形,且
,
平面
,
是
中点,
.
![](https://img.xkw.com/dksih/QBM/2016/7/12/1572913435418624/1572913441038336/STEM/31381705-a1e7-4634-afe2-ce70a179c2b8.png?resizew=178)
(Ⅰ)求证:
平面
;
(Ⅱ)若
,
,求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b41b89ccb8296f8195f84832995d52dd.png)
![](https://img.xkw.com/dksih/QBM/2016/7/12/1572913435418624/1572913441038336/STEM/31381705-a1e7-4634-afe2-ce70a179c2b8.png?resizew=178)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df003447e98fd5ba9badd42177f345db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/218054144a13435580cd132b9459546c.png)
更新时间:2016-12-04 16:43:29
|
相似题推荐
解答题-问答题
|
较难
(0.4)
名校
【推荐1】已知四棱锥
的底面为直角梯形,
,
,
底面ABCD,且
,
,M是PB的中点.
平面
;
(2)判断直线CM与平面
的位置关系,并证明你的结论;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8ef58be8708144272538ee427fb92c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b377f22aafd3742ad860f77abaacef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de217862f189f14a9ffa0c40f5368f6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)判断直线CM与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e9a8d2e4172812913af13badafa4dbb.png)
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解答题-问答题
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较难
(0.4)
【推荐2】在正三棱台
中,侧棱长为1,且
为
的中点,
为
上的点,且
.
(1)证明:
平面
,并求出
的长;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08b818b60f9446b01e086502cfb7dac6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea2ea6ce533bd6f40967e6bee24c2b94.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/24/a0948a2f-601f-4d4b-bd3f-4cab165bc4ef.png?resizew=160)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
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解答题-证明题
|
较难
(0.4)
名校
【推荐1】在如图所示的几何体中,
平面
平面
,记
为
中点,平面
与平面
的交线为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/24/6e96ab0a-5534-429d-9689-741dbe819626.png?resizew=153)
(1)求证:
平面
;
(2)若三棱锥
的体积
与几何体
的体积
满足关系
为
上一点,求当
最大时,直线
与平面
所成角的正弦值的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd654221ab95fe241d9e0202443f2609.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83e8bc25f90e297e93bcd80fd8681c73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40a9690e97521abd2ceabd2eff97d136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8010e1a73f05117a278860c1c0c7f147.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8257b6bd25104e07b9ad935c0a3aac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/24/6e96ab0a-5534-429d-9689-741dbe819626.png?resizew=153)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9df740160690029ac1e730c85f20347.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5d90f940f5693b22ddf2e7c761887d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4764374bd2fb78e59cd0b283637baeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63055a5d6916f99d07fede49120753f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724354f18e865b3949881d57d71ef6da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63055a5d6916f99d07fede49120753f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
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解答题-问答题
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较难
(0.4)
【推荐2】如图所示,平面
平面ABC,
是等腰直角三角形,
,四边形ABDE是直角梯形,
,
,
,O,M分别为CE,AB的中点.
![](https://img.xkw.com/dksih/QBM/2022/4/27/2967029765120000/2969160018657280/STEM/ec003906-d1ec-4410-9c96-df657ff8acbc.png?resizew=188)
(1)试判断直线OD与平面ABC的位置关系,并说明理由;
(2)求直线CD和平面ODM所成的角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31effd1d3f7ce1f6e57be80c7f3af4ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08313da7b66283d2e0b3987f3e6761f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cce757d4d377760fe5a21f47c838dd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a22940cd2a129350c952ad7dc6db924.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/514ab3791431088948816c4ba7514c58.png)
![](https://img.xkw.com/dksih/QBM/2022/4/27/2967029765120000/2969160018657280/STEM/ec003906-d1ec-4410-9c96-df657ff8acbc.png?resizew=188)
(1)试判断直线OD与平面ABC的位置关系,并说明理由;
(2)求直线CD和平面ODM所成的角的正弦值.
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