如图,四面体
的每条棱长都等于
,
,
分别是
,
的中点.记
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/b3e8f509-74a9-43cc-9b54-3475b6d8b012.png?resizew=194)
(1)用
,
,
表示
;
(2)求直线
与直线
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f550d33a4813211cbed34fb6823ac66d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9ba16eaca1d805e882917e88efa9838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40e5bfffa8877507d64dcfc7c04f580a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/b3e8f509-74a9-43cc-9b54-3475b6d8b012.png?resizew=194)
(1)用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ae98586d80f892771c90ab39eaced90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee437e6ff470c2f67b8429f57b90ae37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94a87c03982d3af82c243fe0cca504f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc77f6f4e0bf9f7cf90b84d071210bd6.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
更新时间:2021-11-24 22:55:21
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】如图,已知
在平面
内,D是斜边
的中点,
,且O到平面
的距离为
,
,
,求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8807117d0d649419fdda04c531cdc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d31b274c4f82533ea4454388ed4f7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/689ff84e2d7f52c7446ef789a54557da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dafddfd80f69337909f6eac0f0dbfd59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432043f79e122f291c47453013042704.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07fc6b6fa72d2af776a69c54fc6440f4.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】如图所示,在正方体
中,点
在
上,且
,点
在体对角线
上,且
.求证:
,
,
三点共线.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/514430dbd70d1d1fb2ae57c8e518f4e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/958dac59a6aaa584b55dfb55d77ae6ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
您最近一年使用:0次
【推荐1】在长方体
中,
,
,
,E为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/47ef1d11-3885-4321-ae72-27fab92d852f.png?resizew=112)
(1)求直线
与
所成角的余弦值;
(2)若F为BC的中点,求直线
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/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92535536bd3c2761724fd058427f95a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/3/47ef1d11-3885-4321-ae72-27fab92d852f.png?resizew=112)
(1)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/becf2941e15d668d93ea6ed980afd0ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
(2)若F为BC的中点,求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/becf2941e15d668d93ea6ed980afd0ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2026c6fcd557c9f3da4416d9c53098aa.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,在几何体
中,平面四边形
是菱形,平面
平面
,
,且
,
,
.
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c897a54f2e36bc4b52fba74b41c89d2d.png)
(2)若二面角
是直二面角,求直线
与直线
所成角的余弦值.
![](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/ed9c7b69462dc9226e35ddac8f179cf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27fcafd4e3c295eed2ab9c92c3d4a36b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/179071147b940f5e2f80e74526cebf92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1496042c1d721cffd25053e997a9a97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e46571701ccaa18d3c844ab99ee6c30e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/1/8b06071a-a884-40ba-8b80-0ae73d70dfc2.png?resizew=162)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c897a54f2e36bc4b52fba74b41c89d2d.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a34e44c5d7e1d22521fb293994f5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735056c174e8dd7906257a2a50a962a7.png)
您最近一年使用:0次