题目内容
如图:探照灯、锅形天线、汽车灯以及其它很多灯具都与抛物线形状有关,如图所示是一探照灯灯碗的纵剖面,从位于![](http://thumb.1010pic.com/pic1/imagenew2/czsx/8/24168.png)
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/9/24169.png)
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/10/24170.png)
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/11/24171.png)
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/12/24172.png)
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/13/24173.png)
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/1/36141.jpg)
A.![]() | B.![]() | C.![]() | D.![]() |
p;【答案】B解析:
解:过O点向左作射线OE,使OE∥AB,则OE∥CD,![](http://thumb.1010pic.com/pic1/imagenew2/czsx/18/24178.png)
∴∠EOB=∠ABO=α,∠EOC=∠DCO=β,
即∠BOC=∠BOE+∠EOC=α+β.
故选B.
解:过O点向左作射线OE,使OE∥AB,则OE∥CD,
![](http://thumb.1010pic.com/pic1/imagenew2/czsx/18/24178.png)
∴∠EOB=∠ABO=α,∠EOC=∠DCO=β,
即∠BOC=∠BOE+∠EOC=α+β.
故选B.
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