题目
题型:不详难度:来源:
(1)若最大拱高h为6m,则拱宽
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-34441.gif)
(2)若最大拱高h不小于6m,则应如何设计拱高h和拱宽
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-34441.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-15066.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-23009.jpg)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-64647.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-90918.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-93370.gif)
解析
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145031-56826.gif)
点(11,4.5)及
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145031-28398.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145031-35522.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145031-42973.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-64647.gif)
(2)由椭圆方程得
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145032-20610.gif)
因为
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145032-30048.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145032-72099.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145031-42973.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-90918.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145030-93370.gif)
核心考点
试题【如图,某隧道设计为双向四车道,车道总宽22m,要求通行车辆限高4.5m,隧道全长2.5km,隧道的拱线近似地看成半个椭圆形状。(1)若最大拱高h为6m,则拱宽应】;主要考察你对抛物线的定义与方程等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145025-96785.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145025-45707.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145025-46281.png)
▲ .
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145003-85198.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145003-55384.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145003-85198.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145004-24624.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145004-82560.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145004-19446.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145004-55240.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025145005-57149.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144929-20731.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144929-12522.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144929-93840.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144929-42246.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144930-37261.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144930-84783.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144930-67917.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144930-90854.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144930-90042.png)
(Ⅰ)证明:点
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144929-12522.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144931-59296.png)
(Ⅱ)设
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144931-63516.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144931-87598.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144930-90854.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144921-84037.gif)
(I)求抛物线C的焦点坐标;
(II)若点M满足
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144921-83897.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144906-52047.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144906-27123.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191025/20191025144906-60537.gif)
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