在棱长为
的正方体
中,
是
的中点.
![](https://img.xkw.com/dksih/QBM/2020/8/8/2523556104372224/2524731696578560/STEM/a3482f9802f24bf48363222e85c8d3fc.png?resizew=224)
(1)求直线
与
所成角的余弦值;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3da8c338342e38c9aa3f274c053fd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2020/8/8/2523556104372224/2524731696578560/STEM/a3482f9802f24bf48363222e85c8d3fc.png?resizew=224)
(1)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5d9c105f5558d48cc42218ed2b3ef4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff043336d65d3290d36f465f5657674a.png)
19-20高一下·江苏扬州·阶段练习 查看更多[3]
更新时间:2020-08-10 11:22:41
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,长方体
中,
分别是
,
的中点,
分别是
,
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/2020/7/13/2505228785213440/2506584629510144/STEM/5205ad0d-c8da-4f3e-b4e4-12a27be08da5.png)
(1)求证:
平面
;
(2)求二面角
的正弦值;
(3)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/666e81326945f168fc30291f1bb2fc10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e539f26ed5e0b20ff7220559324869a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f59217a50f2f2e91e298f29ada79ee19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4217f4375caaeef4d4221143d5f6bbf.png)
![](https://img.xkw.com/dksih/QBM/2020/7/13/2505228785213440/2506584629510144/STEM/5205ad0d-c8da-4f3e-b4e4-12a27be08da5.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebb05874eb3353d754af24c9974273e.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/502f49e759b623b5c3a8b901bb9882cc.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1934da56321ee721f8bebc1500054ee.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】(1)给出两块相同的正三角形纸片(如图1、图2),要求用其中一块剪拼成一个正三棱锥模型,另一块剪拼成一个正三棱柱模型,使它们的全面积都与原三角形的面积相等.请设计一种剪拼方法,分别用虚线标示在图1、图2中,并作简要说明.
(2)试比较你剪拼的正三棱锥与正三棱柱的体积的大小.
(3)如果给出的是一块任意三角形的纸片(如图3),要求剪拼成一个直三棱柱模型,使它的全面积与给出的三角形的面积相等呢?
(2)试比较你剪拼的正三棱锥与正三棱柱的体积的大小.
(3)如果给出的是一块任意三角形的纸片(如图3),要求剪拼成一个直三棱柱模型,使它的全面积与给出的三角形的面积相等呢?
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,在三棱柱
中,侧棱垂直于底面,
分别为
的中点.求证:
(1)
平面
;
(2)
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bac115dbe2a5f6d74d150dd6b671cff3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00d061c7a9c98768ead226c27bdfd2f0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/7/3293b730-22a2-451c-9aac-4ca6591cf8f8.png?resizew=150)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac480d8d9d7821b62a603cf5cfda236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bf9628142422a4884bd59538da6d312.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6d06903252260d31d1a9cdeb735b089.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4739afd7311501e948aa4e1e5c1cb17.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】在直三棱柱
中,
,D是AB中点,
.
(1)证明:
//平面
.
(2)求异面直线
与
所成角的大小;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b51da47ab8433342f7a319e412fefae.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/3/13f6280a-e674-4a3c-8281-d3a4d07dc2b0.png?resizew=132)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0772e18d6605a5c10ade8b5ecd1ae77.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.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】在直三棱柱
中,
,
,
,D是
的中点.
平面
;
(2)求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4622aff92fac94916af14f0e913e021.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4557a368725226f2c8ea2efb7d30e478.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc7e774e4ae40c23bf4ceed179230ca.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.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1】如图,三棱锥
中,
平面
,
,
,D是
的中点,E是
的中点,点F在
上,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/25/cc2bc73e-bee8-4e24-8005-38545dc94336.png?resizew=180)
(1)证明:
平面
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc372b6fd2c0415bf2a3a3b04f547b49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afb18c7c5391647214d4da31a88202d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7767c6cd2d6039b1a529cc3d2e041303.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be80c18514f919df9730c720fd8fd345.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a89bad23f4e4bb39b8e4de6a9441422.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/25/cc2bc73e-bee8-4e24-8005-38545dc94336.png?resizew=180)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a407b262c22419f73396170ecdc849.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d7d1ab8fe7214fb8b99beb88440240c.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】己知如图,在矩形
中,
,将
沿着
翻折至
处,得到三棱锥
,过M作
的垂线,垂足为
.
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4661615c1b22a44ed1396d5f05831967.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b9f0296c53918018745f4e3906e2dd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71719fa9855745e17362dc00fe945ce2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e261c02846b9c842b77e7792481ad6e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d100d4051c41cab43668f800fa2693bc.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b70049601f57c8a2ece170c0a9c3c05.png)
您最近一年使用:0次