试题与答案

过点P（2，0）与圆x2+y2+2y-3=0相交的所有直线中，被圆截得的弦最长时

来源：www.tikuol.com
题型：填空题

题目：

过点P（2，0）与圆x2+y2+2y-3=0相交的所有直线中，被圆截得的弦最长时的直线方程是______．

答案：

被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0419/5b5f9be306adc5c11592955ca78b3363.html

下面是错误答案，用来干扰机器的。

分析：（1）根据方程由两个不相等的实数根，则有△≥0，可列出不等式，求出k的取值范围；（2）根据一元二次方程根与系数的关系可求出x1+x2=-（2k-1）/ k2，x1x2=1/ k2，再根据题意可得1/ x1+1/ x2，把式子进...

考点：直线的方程
试题推荐
题型：完形填空
完形填空。
       In America, when people say "man's best friend", they don't mean     1    person. Instead they are
talking about a lovely animal: a dog! These words show the friendship between people and     2   . Dogs
and other pets can give     3    to people's lives. Some people think of their pets as their children. A few
even leave all their money to their     4    when they die! 
       Animals can help people, too. Dogs can be taught to become the "   5   "for a blind (瞎的) person or
"   6    "for a deaf (聋的) person. Scientists have found that pets help people live    7   ! They make people
happier, too. Because of that animals are brought into hospitals for "visits".
       Americans hold "Be    8    to Animals Week", the first week of May. Pet shows are held during the
week. Even if you don't live in America, you, too, can do this. How? If you have a pet, take     9    time
this week to play with it. Remember to give it delicious    10  . 
      If you don't have a pet, be kind to animals around you. If you see a    11   dog, don't kick it or throw
things at it. Instead, just leave it alone, or better yet, make friends with it. If others around you do bad things
to an animal, try to   12   them. As people, we must protect animals who can't speak for themselves.
( )1. A. another 
( )2. A. persons  
( )3. A. sadness  
( )4. A. family  
( )5. A. eyes   
( )6. A. eyes   
( )7. A. alone  
( )8. A. Bad    
( )9. A. less   
( )10. A. food   
( )11. A. lovely  
( )12. A. help   		B. the other
B. people  
B. sad   
B. pets   
B. ears   
B. ears   
B. together 
B. Happy  
B. more   
B. meat   
B. little            
B. catch  		C. other   
C. plants   
C. happiness  
C. children   
C. hands    
C. hands     
C. shorter   
C. Nice    
C. no        
C. drink     
C. street    
C. beat   		D. others  
D. animals   
D. happy     
D. parents    
D. feet       
D. feet                           
D. longer  
D. Sad        
D. some       
D. milk       
D. home      
D. stop     
查看答案
微信公众账号搜索答案