如图,在长方体
中,
.
平行于平面
;
(2)求直线
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f932525f21b62dfc7978837e33010f25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fefd8229243bcbee5ac197740e6c66ab.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fefd8229243bcbee5ac197740e6c66ab.png)
更新时间:2017-10-12 19:19:31
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图1,已知正方形
的边长为
,
分别为
,
的中点,将正方形
沿
折成如图2所示的二面角,且二面角的大小为
,点
在线段
上(包含端点)运动,连接
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/a2e1f751-485f-4f64-8a9c-98d0550fc041.png?resizew=327)
(1)若
为
的中点,直线
与平面
的交点为
,试确定点
的位置,并证明直线
平面
.
(2)是否存在点
,使得直线
与平面
所成的角为
?若存在,求此时平面
与平面
的夹角的余弦值;若不存在,请说明理由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/260200d547998bcac50a4a491382e7f4.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/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/18/a2e1f751-485f-4f64-8a9c-98d0550fc041.png?resizew=327)
(1)若
![](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/907d5147cea4c9ce855074864fe54506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6072ec6dfc0203cabb1fe289a5ddc8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558ce69401f3c97930f00ba0e2aa6647.png)
(2)是否存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558ce69401f3c97930f00ba0e2aa6647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/260200d547998bcac50a4a491382e7f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/711da913d92fc989e581bcfdfe092a18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f636f76d550dfb593a25eb680cff556.png)
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解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,在三棱锥
中,
,D为
中点,M为
中点,且
是正三角形,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/9bbefe5d-6f20-4915-a6d5-7d629f425587.png?resizew=188)
(1)求证:
平面
;
(2)求证:平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0bb4ef08f6070a6bbc54ea9c4f130d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/036de574712cad14bddadf6653c7e714.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/9bbefe5d-6f20-4915-a6d5-7d629f425587.png?resizew=188)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0457394ce4f2dc8d940c565c94dcf557.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】如图1,在直角梯形ABCD中,
, 点E为AC中点.将三角形ADC沿AC折起, 使平面ADC
平面ABC,得到几何体D-ABC,如图2所示.
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794400495550464/1795818798546944/STEM/9440072f0786495395f4f42366e35259.png?resizew=239)
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794400495550464/1795818798546944/STEM/8a3a0bc0243c48969121b26ed6e1f6ff.png?resizew=233)
(I)在CD上找一点
,使AD//平面
;
(II)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57a46770d1f143b46b9dc1910a75663f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794400495550464/1795818798546944/STEM/9440072f0786495395f4f42366e35259.png?resizew=239)
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794400495550464/1795818798546944/STEM/8a3a0bc0243c48969121b26ed6e1f6ff.png?resizew=233)
(I)在CD上找一点
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794400495550464/1795818798546944/STEM/8d8d44d2f8db459295eb37c2c0672a0a.png?resizew=17)
![](https://img.xkw.com/dksih/QBM/2017/10/13/1794400495550464/1795818798546944/STEM/0a8c12a361734a7dbd4d11e8074a8364.png?resizew=35)
(II)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,直三棱柱
中,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/d32b28ed-9afa-45d1-aea3-bb76d59d9ae2.png?resizew=192)
(I)若
为
上的一点,且
与直线
垂直,求
的值;
(Ⅱ)在(I)的条件下,设异面直线
与
所成的角为45°,求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4339a40ae9d1947ec3a4b3e2fa3a16cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/d32b28ed-9afa-45d1-aea3-bb76d59d9ae2.png?resizew=192)
(I)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbd338233af4b4df188757fbf642098f.png)
(Ⅱ)在(I)的条件下,设异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f49359083408831925dc1dcb29c9e08.png)
您最近一年使用:0次