如图,三棱台
中,
,
,
为
中点.
(1)证明:平面
平面
;
(2)求直线
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64cb5ba44ba55078171b77534ea44b3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/28/f7c088db-e117-4651-8aa1-4ea73a800cc5.png?resizew=170)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05663419cc1e71688b70688376889e0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edc9ffc43a56921fe79f8602636b8b0f.png)
更新时间:2023-11-07 22:06:18
|
相似题推荐
【推荐1】如图所示,已知圆柱
内接直三棱柱
,
过圆柱底面圆心O,D,E分别是棱
,
上的点,
是
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/2021/12/15/2873188753981440/2925326712840192/STEM/08c6984047cc4c41ade6c0fab44a41d2.png?resizew=181)
(1)求证:平面
平面
;
(2)若直线
与平面
所成角为45°,求
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192f4f9446c954a291f779d963f90257.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b3e730a4075389fe426cd50311b0a29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33de9b94a20b9d6ea37cfe135d790801.png)
![](https://img.xkw.com/dksih/QBM/2021/12/15/2873188753981440/2925326712840192/STEM/08c6984047cc4c41ade6c0fab44a41d2.png?resizew=181)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41207ee90c2c147d2f53b7dfb5dd2680.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cdc08e1c4a04a18d5ecea03393e36d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec353880a1e680a37ecce3b6fb4896f3.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,正方体
的棱长为
,点
在线段
上,且
.
![](https://img.xkw.com/dksih/QBM/2022/7/6/3016830414798848/3019125101969408/STEM/dbbdba6332e14eeaa575dc7355430487.png?resizew=153)
(1)求证:平面
平面
;
(2)画出正方体
被平面
截得的截面,并求该截面的周长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03e27b51082c9a26197f86fce369798f.png)
![](https://img.xkw.com/dksih/QBM/2022/7/6/3016830414798848/3019125101969408/STEM/dbbdba6332e14eeaa575dc7355430487.png?resizew=153)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba0fbd88fdb064072eedd136e9cb41ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
(2)画出正方体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46b91c857bbe3c4f0f08dd2a4124a96e.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在四边形ABCD中,AB//CD,∠ABD=30°,AB=2CD=2AD=2,DE⊥平面ABCD,EF//BD,且BD=2EF.
(Ⅰ)求证:平面ADE⊥平面BDEF;
(Ⅱ)若二面角C
BF
D的大小为60°,求CF与平面ABCD所成角的正弦值.
(Ⅰ)求证:平面ADE⊥平面BDEF;
(Ⅱ)若二面角C
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bfc339cf6dd66599db64fa3fa44e608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bfc339cf6dd66599db64fa3fa44e608.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,在四棱锥
中,底面ABCD为矩形,
平面ABCD,
为BC中点,
为PA中点,
.
(1)证明:
平面PCD;
(2)求直线MN与平面PBC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.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/4a3bd3ec01a846bfb07ff53561d6c87d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/30/1a29a1ed-a220-4229-ae0b-3444b0d7eabe.png?resizew=164)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
(2)求直线MN与平面PBC所成角的正弦值.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】如图,在三棱柱
中,
为正三角形,
,
,
,点
在线段
上,且
.
![](https://img.xkw.com/dksih/QBM/2020/8/13/2527151783485440/2529352430706688/STEM/f7db8ac3-9190-4cba-93f2-b1468393b9a6.png)
(1)证明:
;
(2)求
和平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d430dcf5a02b1e1c23e01ad1bf8a03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c9d5815dc775d5a5810fff0b016a8d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00de3b5f3920068743971c8f05638863.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bf821ca9421940a4ccf8bd03534b4b9.png)
![](https://img.xkw.com/dksih/QBM/2020/8/13/2527151783485440/2529352430706688/STEM/f7db8ac3-9190-4cba-93f2-b1468393b9a6.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33d1a365832df6937ff1411728420538.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/022129b7ae91e9a6a8badb203d2045a1.png)
您最近一年使用:0次