解题方法
1 . 如图所示,已知多面体
的底面
是边长为6的菱形,
底面
且
.
![](https://img.xkw.com/dksih/QBM/2023/4/12/3214835171000320/3216851048341504/STEM/858ebd4f8ae14e6fa20f81a22613a9be.png?resizew=156)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
平面
;
(2)若
,求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9bf53e97203aa720fe3a09b9bf534af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be53e8e1df7be0710a6e603a2bda33fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11052bdbecec59baa298d1dedac28523.png)
![](https://img.xkw.com/dksih/QBM/2023/4/12/3214835171000320/3216851048341504/STEM/858ebd4f8ae14e6fa20f81a22613a9be.png?resizew=156)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4d781525777c7b5284dffc70b2a28a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05740f0c6071846227dc0ec177ad15e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
您最近一年使用:0次
2023-04-15更新
|
2036次组卷
|
2卷引用:第13章 立体几何初步(B卷·能力提升)-【单元测试】2022-2023学年高一数学分层训练AB卷(苏教版2019必修第二册)
解题方法
2 . 如图,在三棱锥
中,
,侧面
为等边三角形,侧棱
.
![](https://img.xkw.com/dksih/QBM/2016/4/15/1572595225706496/1572595231604736/STEM/6e84d7cdd2e541728c9916719f542079.png?resizew=182)
(1)求证:
;
(2)求证:平面
⊥平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fac01527cf9f9f8b55f6a8ad6c013a8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ced8225ff27c8e3e1897b8629312d5.png)
![](https://img.xkw.com/dksih/QBM/2016/4/15/1572595225706496/1572595231604736/STEM/6e84d7cdd2e541728c9916719f542079.png?resizew=182)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e4b16c2c6c9bd089da78122e9d2511.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
您最近一年使用:0次
2016-12-04更新
|
412次组卷
|
2卷引用:第13章《立体几何初步》单元达标高分突破必刷卷(基础版)-2022-2023学年高一数学《考点·题型·技巧》精讲与精练高分突破系列(苏教版2019必修第二册)