名校
1 . 如图,四棱锥中
,
,
与
都是边长为2的等边三角形,
是
的中点.
(Ⅰ)求证:
平面
;
(Ⅱ)求平面
与平面
所成二面角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afc425b071356d9d3d591b3a09358911.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7ee81b6066188abee9d167b6c7f3f71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53502463cc76201000e02df314e58769.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6e2903ff33266528a7902ad51cf8d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31c34b18525831f3eda7bb90be0199b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(Ⅱ)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://img.xkw.com/dksih/QBM/2017/3/10/1641017003319296/1641067728494592/STEM/45f25ec75504418a9e13a9b28e081a5f.png?resizew=228)
您最近一年使用:0次
2017-03-10更新
|
932次组卷
|
3卷引用:浙江省杭州市第二中学2020届高三上学期开学考试数学试题
2014·全国·一模
名校
2 . 直线2x﹣3y+1=0的一个方向向量是( )
A.(2,﹣3) | B.(2,3) | C.(﹣3,2) | D.(3,2) |
您最近一年使用:0次
2016-12-03更新
|
945次组卷
|
7卷引用:浙江省杭州市第四中学下沙校区2023-2024学年高二上学期期中数学试题
2014·浙江·一模
3 . 已知四棱锥P—GBCD中(如图),PG⊥平面GBCD,GD∥BC,GD=
BC,且BG⊥GC,GB=GC=2,E是BC的中点,PG=4
![](https://img.xkw.com/dksih/QBM/2014/4/29/1571694949064704/1571694954897408/STEM/5a325925a5f94efb9760751e16d375cf.png)
(1)求异面直线GE与PC所成角的余弦值;
(2)若F点是棱PC上一点,且
,
,求
的值.
![](https://img.xkw.com/dksih/QBM/2014/4/29/1571694949064704/1571694954897408/STEM/44f8a2a32b11460ba7c9a469bc887566.png)
![](https://img.xkw.com/dksih/QBM/2014/4/29/1571694949064704/1571694954897408/STEM/5a325925a5f94efb9760751e16d375cf.png)
(1)求异面直线GE与PC所成角的余弦值;
(2)若F点是棱PC上一点,且
![](https://img.xkw.com/dksih/QBM/2014/4/29/1571694949064704/1571694954897408/STEM/edcac20d909f4a5881123344c0e1642c.png)
![](https://img.xkw.com/dksih/QBM/2014/4/29/1571694949064704/1571694954897408/STEM/1200c780e4c947fa86bb614f842a3322.png)
![](https://img.xkw.com/dksih/QBM/2014/4/29/1571694949064704/1571694954897408/STEM/24b930d086d741efa4ef217c56832722.png)
您最近一年使用:0次