如图,在侧棱垂直于底面的三棱柱
中,
为侧面
的对角线的交点,
分别为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/caf6aad2-60aa-483b-9be0-9db9bd63eb85.png?resizew=180)
(1)求证:平面
//平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a9a2751ecd970d510d19f2026fc5e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbac36ae3a8f89b82b396aff23234aab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3a51949f48ee8cf746851ba779b078e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/caf6aad2-60aa-483b-9be0-9db9bd63eb85.png?resizew=180)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df21b7b7a47318ef2bb069450c39f1cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9539f8fb13345b449274b67bbda995db.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b2161b1d9379fc32344e8777eef33cd.png)
更新时间:2019-05-05 18:20:40
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】已知直四棱柱
中,底面
为菱形,
,
,
,E为线段
上中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/15/1b504d43-bb0f-4e9c-b55a-d1c8e4425ae3.png?resizew=144)
(1)证明:
平面
;
(2)求
与平面
所成角的正弦值.
![](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/51d0fdc5a00ca0e857b89a7e1420df29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/15/1b504d43-bb0f-4e9c-b55a-d1c8e4425ae3.png?resizew=144)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31c34b18525831f3eda7bb90be0199b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a935b7d21a103a264b6e96ecf82dbe4a.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a935b7d21a103a264b6e96ecf82dbe4a.png)
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【推荐2】如图,在多面体
中,
是正方形,
平面
,
平面
,
,点M为棱
的中点.
![](https://img.xkw.com/dksih/QBM/2020/6/24/2491721298788352/2492093715259392/STEM/009b7e2e182c4d1ea618ba333836ec58.png?resizew=148)
(1)求证:
;
(2)求证:平面
平面
;
(3)若
,
,求E点到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa3c61d6c19e187b4b824b6f5610cdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03687d97d61b4a7cecbb73f2a6604212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://img.xkw.com/dksih/QBM/2020/6/24/2491721298788352/2492093715259392/STEM/009b7e2e182c4d1ea618ba333836ec58.png?resizew=148)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/275d0a87e481621d9aead27445adeefa.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3143afe58004d0d90294803bb712429d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a681d311a864d38cf306a0c137cbcca.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faffe3765c15f53305516895aa595a9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4734735213b599a9915e1ed91a5d8ce4.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,在四棱锥
中,底面ABCD为梯形,
,
平面PDC,且
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/30/c899b9ec-9a1c-4d2d-a220-0335e969df02.png?resizew=164)
(1)若M,F分别是PA,BC的中点,求证:
.
(2)求二面角
的余弦值.
![](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/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e04d8312c0ef5305ebfd7b4e71b317f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88197da08544c0dd0f8fb1359797ac9b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/30/c899b9ec-9a1c-4d2d-a220-0335e969df02.png?resizew=164)
(1)若M,F分别是PA,BC的中点,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1097a13c0408e0709fca27c0f1f5bcd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/715cc9ea5e7d80930284ffb117142770.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】在直三棱柱
中,
分别是线段
的中点,过线段
的中点
作
的平行线,分别
交
于点
.
![](https://img.xkw.com/dksih/QBM/2018/12/13/2095993297747968/2100017497849856/STEM/5d54cce97f164efab8aebb4628de3d58.png?resizew=344)
(1)证明:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ede6a60cad0e0b58e1549fda6e085719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08bd73ff32e065bd5573625c407a31d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b9d7e8634b3ae89a7b3c2d0453d862f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://img.xkw.com/dksih/QBM/2018/12/13/2095993297747968/2100017497849856/STEM/9698e168fc694936b482376d9663d686.png?resizew=4)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62c6f95fb0f50d816861bc3a526aee76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad57e3727b7bbd795b05332fbf9649e9.png)
![](https://img.xkw.com/dksih/QBM/2018/12/13/2095993297747968/2100017497849856/STEM/5d54cce97f164efab8aebb4628de3d58.png?resizew=344)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89c787746bb436d1e28652daa0b269ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9ed537685abbefd48fde1ad7820bcb6.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5329c3bb63c616faf355803cc5d8cefa.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,在矩形
中,将
沿对角线
折起,使点
到达点
的位置,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/66846629-45e9-4147-b166-bce56e03cb8b.png?resizew=443)
(1)求证:
;
(2)若直线
与平面
所成角的正弦值为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baf42acb8d1875acf1775e30ae2e3d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/66846629-45e9-4147-b166-bce56e03cb8b.png?resizew=443)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f92d681685fecaa72dcf38eda81852c.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4d781525777c7b5284dffc70b2a28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf29d07c3751c41ab3503065a5a5052e.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】如图所示的空间几何体中,底面四边形
为正方形,
,
,平面
平面
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2017/5/5/1680697192996864/1682030815256576/STEM/879e823552ba47f28d8c5505c385cabf.png?resizew=189)
(1)求二面角
的大小;
(2)若在平面
上存在点
,使得
平面
,试通过计算说明点
的位置.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ad6f8846d4294ae3789a6ddd17af5b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72c766942d554e7f15ffec6eaacbe0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c674dc5024374f53920947c4cf4baf11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4771d643a2787d9315f9c8f94c2462a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1394fc01d91ffe8e6826cab0c933be3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://img.xkw.com/dksih/QBM/2017/5/5/1680697192996864/1682030815256576/STEM/879e823552ba47f28d8c5505c385cabf.png?resizew=189)
(1)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edd0a3b418f3b1ae176d2e9c5b4987de.png)
(2)若在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2b4e753ef119608188c46a50ec597e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
您最近一年使用:0次