1 . 中国古代有一块著名的“传国玉玺”,印文为“受命于天既寿永昌”,是中国历代正统皇帝的信物,相传西汉末年王莽篡汉,进宫索要玉玺,太后怒而掷之,破其一角,王莽令工匠以黄金补之.现有人想利用“3D打印”技术还原“传国玉玺,做的模型图如图.已知黄金的比重是
(20℃),若使用黄金(约)50g修补破损的一角(假设破损部分为
圆锥体),则该部分底面半径约为_________ .(结果保留小数点后一位).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1041bfa74b53aca8ccf3e137d3a912f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/16/34a2c94c-1bd2-42a3-9bab-d41a7ded8811.png?resizew=181)
您最近一年使用:0次
2023-08-14更新
|
74次组卷
|
2卷引用:河南省鹤壁市高中2022-2023学年高二下学期7月月考数学试题
名校
解题方法
2 . 如图,在直三棱柱
中,
,点D是
的中点,点E在
上,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/19/81649e88-b4a6-4bc6-82ef-60a0a9a174c1.png?resizew=141)
(1)求证:平面
平面
;
(2)当三棱锥
的体积最大时,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/5a8f8e0feaafb269db76c14264de7108.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/810ee7bc82b6f452afb3fc18691abc3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea84e9242d2667cd6a0f7436425ad418.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/19/81649e88-b4a6-4bc6-82ef-60a0a9a174c1.png?resizew=141)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/570723ec1803bb3a69f220ad7df50226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
(2)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a579b221be6ff56a3aee73f250f91c57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea84e9242d2667cd6a0f7436425ad418.png)
您最近一年使用:0次
2023-04-19更新
|
4204次组卷
|
7卷引用:河南省鹤壁市高中2022-2023学年高二下学期第五次段考数学试题
河南省鹤壁市高中2022-2023学年高二下学期第五次段考数学试题四川省雅安市雅安中学2022-2023学年高二下学期期中数学(理)试题广东省广州市2023届高三二模数学试题(已下线)专题04 空间向量与立体几何专题16空间向量与立体几何(解答题)湖南省长沙市周南中学2023届高三二模数学试题(已下线)专题10 立体几何综合-1
名校
解题方法
3 . 如图,在四棱锥
中,底面
是平行四边形,
,侧面
底面
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/8/23/2534261204631552/2542443310964736/STEM/06305e9c-8810-4ede-9ec2-5ba57a5f9a33.png?resizew=153)
(1)求证:
平面
;
(2)过
的平面交
于点
,若
,求三棱锥
的体积.
![](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/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e99998f33ad6edab18180627d4903dcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcaa14690732aac2d2b8e2561ebbc047.png)
![](https://img.xkw.com/dksih/QBM/2020/8/23/2534261204631552/2542443310964736/STEM/06305e9c-8810-4ede-9ec2-5ba57a5f9a33.png?resizew=153)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd9f5de9503f4d71588c16b0ac33742a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bffd3b6cf2e17d221c8aaeb70e81ef48.png)
您最近一年使用:0次
2020-09-04更新
|
385次组卷
|
3卷引用:河南省鹤壁市高级中学2020-2021学年高二上学期阶段性检测(二)数学试题