如图,在正三棱柱
中,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2021/10/20/2833275760254976/2833296692150272/STEM/7d495800-737c-4773-9ec9-9e6fd1874217.png?resizew=250)
(1)证明:
平面
;
(2)已知
,
,求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2021/10/20/2833275760254976/2833296692150272/STEM/7d495800-737c-4773-9ec9-9e6fd1874217.png?resizew=250)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cd597851c0db4e4de4769e10e09383b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bca84ad86c648d3bb20c8909c8da3f.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e862713d078c4f06ec1f15ccd6f5a1f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d72d3b73315c93ed0cd16fa023677152.png)
更新时间:2021-10-20 10:19:47
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】如图①,在直角梯形ABCD中,AB⊥BC,BC∥AD,AD=2AB=4,BC=3,E为AD的中点,EF⊥BC,垂足为F.沿EF将四边形ABFE折起,连接AD,AC,BC,得到如图②所示的六面体ABCDEF.若折起后AB的中点M到点D的距离为3.
(2)求六面体ABCDEF的体积.
(2)求六面体ABCDEF的体积.
您最近一年使用:0次
【推荐2】已知在图1所示的梯形
中,
,
于点
,且
.将梯形
沿
折起,使平面
平面
,如图2所示,连接
,取
的中点
.
![](https://img.xkw.com/dksih/QBM/2020/2/20/2402981574934528/2403673436151808/STEM/bf5e0be8fe5b4112b34c379a8422485d.png?resizew=333)
(1)求证:平面
平面
;
(2)设
,求几何体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b9d54cbbf601f4583659771eb534997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66418ef39d3081d89411a4907d8599f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff24d05b5b9502c2be337f9be84fe4ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ceae9396dc0551b68ac65b5c4648278.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b9d54cbbf601f4583659771eb534997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/306b9504b52df5ad6697fa87200e8a44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://img.xkw.com/dksih/QBM/2020/2/20/2402981574934528/2403673436151808/STEM/bf5e0be8fe5b4112b34c379a8422485d.png?resizew=333)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37f39524e24db3f7c9e2f49f35b5e660.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e781a2489271bfd1597cba1bb6f5887.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fd822117a4338c94ac0c7ab056fc0fb.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,点P是正方形ABCD外一点,PA⊥平面ABCD,PA=AB=2,且E,F分别是AB,PC的中点.
(1)求证:EF//平面PAD;
(2)求证:EF
平面PCD;
(3)求:直线BD与平面
所成角的正弦.
(1)求证:EF//平面PAD;
(2)求证:EF
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
(3)求:直线BD与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6261790c66cc71ee3898afabad0c09f4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/d5c39fff-980a-4162-bcf3-6e6e0ea43ebb.png?resizew=184)
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解答题-证明题
|
适中
(0.65)
【推荐2】在平行六面体
中,已知
为平行四边形
的中心,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/28bfd065-b0dc-4004-974a-6612642f9af7.png?resizew=234)
(1)求证:
平面
;
(2)若
在平面
上的射影为四边形
的中心,
,
,
,求平面
与平面
所成二面角(平面角不大于
)的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bf9ef324f1289e205e29fed105c38e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/28bfd065-b0dc-4004-974a-6612642f9af7.png?resizew=234)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3a04ea8ebc597fd1f5d6bb8df181a2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/299fe914d64f3a06f9b641d5591fc47a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e902ef81301bf5fd07e280c7bf37a034.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e13c772461aef1d9d715129636739748.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a83c0b8db2205a6815811aa4ff5390f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ad72d7565699d1ebb741eb0ce12bac.png)
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解答题-问答题
|
适中
(0.65)
【推荐1】如图,
是棱长为2的正方体,E是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/13/1a2be8a6-2adb-4236-92e6-24ef70fb7acd.png?resizew=171)
(1)证明:
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/13/1a2be8a6-2adb-4236-92e6-24ef70fb7acd.png?resizew=171)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a45b04cc3e5adaeff6f9e01e29032803.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b8a4e30921e17a134092302a93967e2.png)
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解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】已知斜三棱柱
,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/26d0f351-26b0-4f56-a4f7-4c0446cc8b64.png?resizew=164)
(1)求
的长;
(2)求
与面
所成的角的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9723a6e093c297b001436e8932b1820.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f95a09aa385a3591facd2132dde809.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589b2b00f94b93381eb0397e0c93f948.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed1efb2224920c1769400e7222006347.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/26d0f351-26b0-4f56-a4f7-4c0446cc8b64.png?resizew=164)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】如图,四棱柱
中,底面
是矩形,且
,
,
,若
为
的中点,且
.
![](https://img.xkw.com/dksih/QBM/2015/12/24/1572392378597376/1572392381956096/STEM/150e2c67cbed4028984f66de19ae012f.png?resizew=239)
(1)求证:
平面
;
(2)线段
上是否存在一点
,使得二面角
为
?若存在,求出
的长;不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae79b7d1fc4131ae3b9de76e2fa45e5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f436b2f2edf1a47f80a4c439d6938646.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a77ddea1345e7d0685b106cd017f21d.png)
![](https://img.xkw.com/dksih/QBM/2015/12/24/1572392378597376/1572392381956096/STEM/150e2c67cbed4028984f66de19ae012f.png?resizew=239)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01e5981445b6f2a6c58974158d96a4de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/075aa39e7090f88f04abd544ed32b044.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037fb348109dc2063a268b10eb925a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,四棱锥
的底面是正方形,
平面
,
,
,点
是
上的点,且
,
(1)若
,求
和
所成角的余弦值;
(2)设二面角
的大小为
,直线
与平面
所成的角为
,求出
的最大值,并指出此时的
取值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fb2e071d4e01107dcf7d95cbb86b415.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76b961aa27352c0ea54014325c96b5ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfda7a170c4a5b5e61b3e82e4ec30110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5940069ecb7f22cca04d1d386af5def.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/4/ebc3b221-7789-4126-9730-955fa446fb16.png?resizew=137)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500d68f2678989a5ce7431cfd51b019d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
(2)设二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbeab80976db9b4689b9446cda06196a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ef796b46e68fe77b117ff0483d2370c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6581916f5a65edfea257c804efee007e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2592e47a0980c15d061c1975443c3590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,在棱长为2的正方体
中,已知点M在正方形
内部,
,
.
![](https://img.xkw.com/dksih/QBM/2020/5/5/2456257981718528/2456405646606336/STEM/e9f9335143b349859af6eeba0b70e031.png?resizew=181)
(1)经过点M在平面
内作一条直线与
垂直(说明作法及理由);
(2)求直线
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ef25d34878e5bb4532c92ee4bc245b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d58d16c9d123c7c778f7abc3c8331242.png)
![](https://img.xkw.com/dksih/QBM/2020/5/5/2456257981718528/2456405646606336/STEM/e9f9335143b349859af6eeba0b70e031.png?resizew=181)
(1)经过点M在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bf9ef324f1289e205e29fed105c38e.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐3】如图,三棱柱
中,E为
中点,F为
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/27/8309f077-6f42-4428-906e-d7ccb5fb5854.png?resizew=142)
(1)求证:
平面ABC;
(2)若
平面
,求证:
平面ABC.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/27/8309f077-6f42-4428-906e-d7ccb5fb5854.png?resizew=142)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a407b262c22419f73396170ecdc849.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adf6fde6ec44bba7726b6f2d07b3b179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d25e8fc3dda4f8b45491514b6e22a962.png)
您最近一年使用:0次