如图,在直三棱柱
中,
,
,
,
,
分别为
,
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/409fc36e-b96c-4d05-a7c5-c23b3eaccaf8.png?resizew=153)
(1)证明:
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822ba132ca9dd0d4a050659aef3c9b26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/602cdfab573c9cb3ce030f8dba8a9390.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1859959fdb4c5edd8056893f94a10a0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/409fc36e-b96c-4d05-a7c5-c23b3eaccaf8.png?resizew=153)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047da2786ecd6c3b0248908e72593c66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0278f9809e118b80c9946d9b9ae40c83.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0278f9809e118b80c9946d9b9ae40c83.png)
更新时间:2020-02-17 23:58:07
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,已知三棱柱
的侧棱与底面垂直,
,
,
分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/e639154b-cec7-407e-939a-5c41e7c8a29c.png?resizew=138)
(1)证明:
;
(2)判断直线
和平面
的位置关系,并加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.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/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/e639154b-cec7-407e-939a-5c41e7c8a29c.png?resizew=138)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e98e7edbeab52b0aa5d66396ca46124.png)
(2)判断直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
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【推荐2】如图,在三棱锥P-ABC中,PB⊥AC,PB与底面ABC成30°角,
的面积为1.
(1)若PC⊥AB,求证:P在底面ABC的射影H是
的垂心;
(2)当二面角P-AC-B为多少时,
的面积最大?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ab13ef156d034b710d811e09b0be34.png)
(1)若PC⊥AB,求证:P在底面ABC的射影H是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
(2)当二面角P-AC-B为多少时,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794547978231808/1796088174043136/STEM/95f6f5f14c7e48b19044c98f7511655b.png?resizew=178)
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解答题-证明题
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适中
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【推荐1】如图圆柱OO'内接直四棱柱ABCD-A'B'C'D'且AD过圆心O,P为下底面圆上一点.
![](https://img.xkw.com/dksih/QBM/2021/1/5/2629607846649856/2688939229290496/STEM/9e7a9121-ae53-44f1-987f-eca9df26ba70.png?resizew=153)
(1)求证PD'⊥AP
(2)若圆柱的轴截面为边长为4的正方形,
,求D'到平面DA'P的距离.
(3)若
,请添加一个条件求出AP,DP与下底面夹角的正切值
![](https://img.xkw.com/dksih/QBM/2021/1/5/2629607846649856/2688939229290496/STEM/9e7a9121-ae53-44f1-987f-eca9df26ba70.png?resizew=153)
(1)求证PD'⊥AP
(2)若圆柱的轴截面为边长为4的正方形,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead2d8d627109d65934b9319b6cc8a26.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcb838e3ea978a85ba96daffe19ccdc.png)
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【推荐2】在三棱锥
中,
为棱
的中点,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1804c3641953c30ccf750504eff6577.png)
(I)证明:
;
(II)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41e5db1d2fd912f77923e4c120a7dc19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98aa317b5749b75ef4890e264b8bbd8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1804c3641953c30ccf750504eff6577.png)
(I)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfa11c9612235a7200bfb2b6464d4b83.png)
(II)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21665d21bbfb04410c78345de1fd15ae.png)
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