解题方法
1 . 如图,在直三棱柱
中,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/5/27/2471928393375744/2473089068957696/STEM/6d737addf3434b8c8f137c78c43d27ae.png?resizew=170)
(1)设
,异面直线
与
所成角的余弦值为
,求
的值;
(2)若点D是
的中点,求二面角
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/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://img.xkw.com/dksih/QBM/2020/5/27/2471928393375744/2473089068957696/STEM/6d737addf3434b8c8f137c78c43d27ae.png?resizew=170)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f0d53573554894dbe3b31027d7cdfe2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d63588adffe924634e8ec4bb791cb64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(2)若点D是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0ba51c39cd2a199c701a7625e6c94eb.png)
您最近一年使用:0次
解题方法
2 . 已知,如图四棱锥
中,底面
为菱形,
,
,
平面
,E,M分别是BC,PD中点,点F在棱PC上移动.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/29/8ceebc56-c670-4bc1-b363-b723c1d78c84.png?resizew=204)
(1)证明无论点F在PC上如何移动,都有平面
平面
;
(2)当直线AF与平面PCD所成的角最大时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96127e45e2dd2494fccb1c0905951f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/29/8ceebc56-c670-4bc1-b363-b723c1d78c84.png?resizew=204)
(1)证明无论点F在PC上如何移动,都有平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6501f1c913a4ef64957a2f01ab5baa15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)当直线AF与平面PCD所成的角最大时,求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce747dfba7cd1b8054a3fc741629f257.png)
您最近一年使用:0次
2020-05-28更新
|
504次组卷
|
2卷引用:2020届湖北省八校(黄冈中学、华师一附中、襄阳四中、襄阳五中、荆州中学等)高三下学期第二次联考数学(理)试题
3 . 如图1,
,点
为线段
的中点,点
为线段
上靠近
的三等分点.现沿
进行翻折,得到四棱锥
,如图2,且
.在图2中:
![](https://img.xkw.com/dksih/QBM/2020/5/26/2471209337217024/2471687538270208/STEM/9439b224-2678-4d92-84ff-0dbff6155f5f.png?resizew=168)
![](https://img.xkw.com/dksih/QBM/2020/5/26/2471209337217024/2471687538270208/STEM/ca106500-c163-479c-88a0-17166d2aab1d.png?resizew=153)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cb2add1954da7c5365e4ef6a9e8bfa7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d3071be47c0be1fb8b89afe89fe1816.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f70d6f5baadf8139ee650b84f2fde70.png)
![](https://img.xkw.com/dksih/QBM/2020/5/26/2471209337217024/2471687538270208/STEM/9439b224-2678-4d92-84ff-0dbff6155f5f.png?resizew=168)
![](https://img.xkw.com/dksih/QBM/2020/5/26/2471209337217024/2471687538270208/STEM/ca106500-c163-479c-88a0-17166d2aab1d.png?resizew=153)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0edb1508fc95765f3bb316bcb5252d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7af6b531f532eb39c26d36e9dd97254d.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59ac7cf883a6e586d06e3f33875bd95b.png)
您最近一年使用:0次
4 . 如图,在四棱锥
中,
,
,
,底面
为正方形,
、
分别为
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/0a059b16-b677-453e-913e-be5a4a7d6dfd.png?resizew=129)
(Ⅰ)证明:
平面
;
(Ⅱ)求直线
与平面
所成角的正弦值;
(Ⅲ)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9300bfac2806ffc211a19d9b7317e9d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37002ada5d194d4d062fa3285d7d9824.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15eae3c2cb4274a947f6a011960934d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/0a059b16-b677-453e-913e-be5a4a7d6dfd.png?resizew=129)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c2b786c64e6a9ed2ec5670cde74f86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/588690c4a218025937357ffab8d63c7a.png)
(Ⅱ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/588690c4a218025937357ffab8d63c7a.png)
(Ⅲ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae68b15be784a6fa7a62897badf67f27.png)
您最近一年使用:0次
5 . 如图所示,在多面体
中,
平面
,
,点
在
上,点
是
的中点,且
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/25/50a0e3f7-edfa-426e-b675-cecb4095443d.png?resizew=114)
(Ⅰ)证明:
平面
;
(Ⅱ)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/689c065652544780be8b33ae92cbb6d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3dc3d90beb344a2a154a90009b51bcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b62c8b60fa6c119f2f746d66fd289374.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69e6ba36d7fff85dd69dd9e099cf1813.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/25/50a0e3f7-edfa-426e-b675-cecb4095443d.png?resizew=114)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93cf663ee2bf1ac5c43f4306fa0cf250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(Ⅱ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45992234b46d4540bc3f00a5056810cc.png)
您最近一年使用:0次
名校
6 . 如图,四棱锥
的底面
是菱形,
,
,
,
,二面角
的大小为60°.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/37f42625-de34-4c99-b21e-c3c2ae1d3e39.png?resizew=168)
(1)证明:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a58a622e2b1a239f2f96aa1501e9799.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cb96e0331eebe80ed1ff610faf531fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/371853a703a8dafa6f8e942f46cb8706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02dd7f88976eb5975d31b410d0d973.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf29d07c3751c41ab3503065a5a5052e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/37f42625-de34-4c99-b21e-c3c2ae1d3e39.png?resizew=168)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbd7c2767c106faf27d6a97ebc8e739.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cc03a6f8df806225fd34627c9488270.png)
您最近一年使用:0次
2020-05-23更新
|
430次组卷
|
2卷引用:2020届四川省成都市石室中学高三下学期5月月考数学理科试题
19-20高三下·北京·阶段练习
名校
7 . 在四棱柱
中,
平面
,底面
是边长为
的正方形,
与
交于点
,
与
交于点
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/9dac9b91-d433-4b8f-a49d-4a69375655f0.png?resizew=220)
(Ⅰ)证明:
平面
;
(Ⅱ)求
的长度;
(Ⅲ)求直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.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/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c7f786fc33d0506d64047034e12fd7a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/9dac9b91-d433-4b8f-a49d-4a69375655f0.png?resizew=220)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(Ⅱ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(Ⅲ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3533837e3d08c461dea031a44e5424d.png)
您最近一年使用:0次
8 . 如图,菱形
中,
,
为
中点,将
沿
折起使得平面
平面
,
与
相交于点
,
是棱
上的一点且满足
.
![](https://img.xkw.com/dksih/QBM/2020/5/18/2465267479109632/2465526530899968/STEM/565544772d9b419e8ae0fb44c330324d.png?resizew=408)
(1)求证:
平面
;
(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/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d28c625d7ac6878957facc8274d459c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8210bde150614e503abe6cf5945d2e34.png)
![](https://img.xkw.com/dksih/QBM/2020/5/18/2465267479109632/2465526530899968/STEM/565544772d9b419e8ae0fb44c330324d.png?resizew=408)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdc4326d832adea0655b05083e6af7f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ec2524be492bca0d1566bf848066f10.png)
您最近一年使用:0次
2020-05-18更新
|
593次组卷
|
2卷引用:陕西省西安市2020届高三下学期第三次质量检测理科数学试题
解题方法
9 . 如图,在四棱锥
中,平面
平面
,
,
,
,且
.
![](https://img.xkw.com/dksih/QBM/2020/5/12/2461213327876096/2462741089124352/STEM/73825283584940fbad326a20737b817d.png?resizew=189)
(1)过
作截面与线段
交于点H,使得
平面
,试确定点H的位置,并给出证明;
(2)在(1)的条件下,若二面角
的大小为
,试求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cb96e0331eebe80ed1ff610faf531fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37591109b0a0ec5ffe2133f83310eca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95a94fb1f77d2451d00cc745252fe184.png)
![](https://img.xkw.com/dksih/QBM/2020/5/12/2461213327876096/2462741089124352/STEM/73825283584940fbad326a20737b817d.png?resizew=189)
(1)过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/011abe509df00fe9410ab08b585ad7db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c0c35ada784e2702bcc12a405f7ec5.png)
(2)在(1)的条件下,若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9d17eca3a844f9a685e6abf162b0d22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af9955b5aebb73cd84447e8541f901ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c0c35ada784e2702bcc12a405f7ec5.png)
您最近一年使用:0次
2020-05-14更新
|
295次组卷
|
2卷引用:2020届湖南省娄底市高三高考仿真模拟理科数学试题
10 . 如图所示,在三棱柱
中,侧面
为菱形,
,
,侧面
为正方形,平面
平面
.点
为线段
的中点,点
在线段
上,且
.
![](https://img.xkw.com/dksih/QBM/2020/5/12/2461211869208576/2461809766744064/STEM/a1110cff-249c-4897-a013-7f3dfdc90387.png)
(1)证明:平面
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8b5a6dbcf05f572f83f51abf7d668c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61cdaadeae37736a1e6dd93fa1fe712f.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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e2819c0e194dea440eace967c1f461b.png)
![](https://img.xkw.com/dksih/QBM/2020/5/12/2461211869208576/2461809766744064/STEM/a1110cff-249c-4897-a013-7f3dfdc90387.png)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50d9bdbbdfabc737323692c796e41930.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e06947327f4c41340b8713e8a6b4c87.png)
您最近一年使用:0次