11-12高二上·江西宜春·阶段练习
名校
1 . 如图,在三棱锥
中,
,
,点
、
分别是
、
的中点,
底面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/23/7236617a-a79b-4def-8e26-75b912383639.png?resizew=153)
(1)求证
平面
;
(2)当
时,求直线
与平面
所成角的正弦值;
(3)当
取何值时,
在平面
内的射影恰好为
的重心?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61085b97b88eb1f5e5cf196f9d846053.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbc6f007dbf1c1a36eb031e520608403.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/23/7236617a-a79b-4def-8e26-75b912383639.png?resizew=153)
(1)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6072ec6dfc0203cabb1fe289a5ddc8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3a2a34b4317deffa40ba34e269c2b81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05e78042a384255038de485fd7bc0839.png)
您最近一年使用:0次
2023-04-22更新
|
248次组卷
|
5卷引用:2017届山西怀仁县一中高三上学期开学考数学(理)试卷
2017届山西怀仁县一中高三上学期开学考数学(理)试卷(已下线)2011-2012学年江西省上高二中高二上学期第二次月考理科数学试卷浙江省杭州市第四中学下沙校区2022-2023学年高二下学期期中数学试题(已下线)模块三 专题4 空间向量的应用1直线与平面的夹角、二面角 B能力卷(已下线)模块三 专题5 直线与平面的夹角、二面角 B能力卷 (人教B)
解题方法
2 . 在三棱锥
中,平面
平面
,
,
.设D,E分别为PA,AC中点.
![](https://img.xkw.com/dksih/QBM/2019/4/18/2185129949167616/2185998087766016/STEM/16cc90411a0448a989d79340c45ca90b.png?resizew=185)
(Ⅰ)求证:
平面PBC;
(Ⅱ)求证:
平面PAB;
(Ⅲ)试问在线段AB上是否存在点F,使得过三点D,E,F的平面内的任一条直线都与平面PBC平行?若存在,指出点F的位置并证明;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d9ef979b9f27a28cbda6923e888ccc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://img.xkw.com/dksih/QBM/2019/4/18/2185129949167616/2185998087766016/STEM/16cc90411a0448a989d79340c45ca90b.png?resizew=185)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063510e3c1fb6a7ccc3b8e3e3c7d660e.png)
(Ⅱ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
(Ⅲ)试问在线段AB上是否存在点F,使得过三点D,E,F的平面内的任一条直线都与平面PBC平行?若存在,指出点F的位置并证明;若不存在,请说明理由.
您最近一年使用:0次
2019-04-19更新
|
1902次组卷
|
8卷引用:2017届山西怀仁县一中高三上学期开学考数学(文)试卷
2010·北京西城·一模
名校
3 . 在四棱锥
中,侧面
底面
,
,
为
中点,底面
是直角梯形,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/8/13/2527151783485440/2529352429617152/STEM/7ce877516d1c498fb0e2348ee15106ad.png?resizew=190)
(1)求证:
平面
;
(2)求证:
平面
;
(3)设
为侧棱
上一点,
,试确定
的值,使得二面角
为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/342d452a7b850cd3a15b23619ad39bd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37002ada5d194d4d062fa3285d7d9824.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4795ee1f96b430529934e2231b38885d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16114c73382b18f060150f2ab1f1484d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://img.xkw.com/dksih/QBM/2020/8/13/2527151783485440/2529352429617152/STEM/7ce877516d1c498fb0e2348ee15106ad.png?resizew=190)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ba7a4f5ec17e1792c9a7ed23349bbbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32bff9fff7a158e95a7f5041629e7a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
您最近一年使用:0次
2020-08-17更新
|
274次组卷
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6卷引用:山西省怀仁市第一中学云东校区2020-2021学年高二下学期第一次月考(入学考试)数学(理)试题
山西省怀仁市第一中学云东校区2020-2021学年高二下学期第一次月考(入学考试)数学(理)试题(已下线)北京市西城区2010年高三一模数学(理)试题(已下线)2010年靖安中学高三高考模拟考试数学卷2020届河北省新乐市第一中学高三下学期高考冲刺数学试题(已下线)专题20 立体几何综合-2020年高考数学(理)母题题源解密(全国Ⅱ专版)新疆乌鲁木齐市第七十中学2020-2021学年高二上学期期末考试数学(理)试题