名校
1 . 无数次借着你的光,看到未曾见过的世界:国庆七十周年、建党百年天安门广场三千人合唱的磅礴震撼,“930烈士纪念日”向人民英雄敬献花篮仪式的凝重庄严
金帆合唱团,这绝不是一个抽象的名字,而是艰辛与光耀的延展,当你想起他,应是四季人间,应是繁星璀璨!这是开学典礼中,我校金帆合唱团的颁奖词,听后让人热血沸腾,让人心向往之.图1就是金帆排练厅,大家都亲切的称之为“六角楼”,其造型别致,可以理解为一个正六棱柱(图2)由上底面各棱向内切割为正六棱台(图3),正六棱柱的侧棱
交
的延长线于点
,经测量
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9edf5b5d5de0dc8433f8e49b93d79e7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/dae99132-bfad-4b9d-b1fe-601d36cad5e6.png?resizew=150)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/8eeda22d-adba-4dfe-b56f-c8331e954444.png?resizew=163)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/40498824-4beb-4838-b919-a133b83c7ecb.png?resizew=191)
(1)写出三条正六棱台的结构特征.
(2)“六角楼”一楼为办公区域,二楼为金帆排练厅,假设排练厅地板恰好为六棱柱中截面,忽略墙壁厚度,估算金帆排练厅对应几何体体积.(棱台体积公式:
)
(3)“小迷糊”站在“六角楼”下,陶醉在歌声里.“大聪明”走过来说:“数学是理性的音乐,音乐是感性的数学.学好数学方能更好的欣赏音乐,比如咱们刚刚听到的一个复合音就可以表示为函数
,你看这多美妙!”
“小迷糊”:“.....”
亲爱的同学们,快来帮“小迷糊”求一下
的最大值吧.
注:可以参考(不限于)下面公式:
①
元均值不等式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faa52b46f115de52814795d65da5238f.png)
②琴生不等式:
若函数
在
上为“凸函数”,且
为
上任意
个实数,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1821e1ae466356718b3fc4e616fb8503.png)
注:
在
是“凸函数”
③柯西不等式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c54ff21406dc68cdab0d21351daf51.png)
注:其二元形式为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eece548f90ab9654e1dd55340431f4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e4fa04825ac7d071968056322d88be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f92a8ba0b29a1e1eca637c01b7f39b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9edf5b5d5de0dc8433f8e49b93d79e7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/dae99132-bfad-4b9d-b1fe-601d36cad5e6.png?resizew=150)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/8eeda22d-adba-4dfe-b56f-c8331e954444.png?resizew=163)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/13/40498824-4beb-4838-b919-a133b83c7ecb.png?resizew=191)
(1)写出三条正六棱台的结构特征.
(2)“六角楼”一楼为办公区域,二楼为金帆排练厅,假设排练厅地板恰好为六棱柱中截面,忽略墙壁厚度,估算金帆排练厅对应几何体体积.(棱台体积公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7850942557a95467b4159b86c1f25678.png)
(3)“小迷糊”站在“六角楼”下,陶醉在歌声里.“大聪明”走过来说:“数学是理性的音乐,音乐是感性的数学.学好数学方能更好的欣赏音乐,比如咱们刚刚听到的一个复合音就可以表示为函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3387b0d9e635720bbbe3fe28b536200.png)
“小迷糊”:“.....”
亲爱的同学们,快来帮“小迷糊”求一下
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3888740fa8b552b55b4a0c8ae4166007.png)
注:可以参考(不限于)下面公式:
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faa52b46f115de52814795d65da5238f.png)
②琴生不等式:
若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fe1c31a81f198c443e71b83ca662939.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1821e1ae466356718b3fc4e616fb8503.png)
注:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3162d2c7b650bba3e401ffbb1e13bb45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3ff8dca35b759d3051b62badd7d76bc.png)
③柯西不等式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c54ff21406dc68cdab0d21351daf51.png)
注:其二元形式为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d115a39e93fabee911c86269199e13d0.png)
您最近一年使用:0次
2 . 已知x,y,z是3个大于等于1的实数,那么
最小值写成最简分数后分子分母之和是___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58fcd69b1c9e63b91b0274cc02b80c91.png)
您最近一年使用:0次