已知P={（x，y）|（x+2）2+（y-3）2≤4}，Q={（x，y）|（x+_爱下问搜题

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问题解答题

已知P={（x，y）|（x+2）²+（y-3）²≤4}，Q={（x，y）|（x+1）²+（y-m）²＜

1

4

}，且P∩Q=Q，求m的取值范围．

答案

点集P表示平面上以O₁（-2，3）为圆心，

2为半径的圆所围成的区域（包括圆周）；

点集Q表示平面上以O₂（-1，m）为圆心，

1

2

为半径的圆的内部．

要使P∩Q=Q，应使⊙O₂内含或内切于⊙O₁．

故有|O₁O₂|²≤（R₁-R₂）²，即（-1+2）²+（m-3）²≤（2-

1

2

）²．

解得3-

5

2

≤m≤3+

5

2

．

改错题

短文改错。只有一行正确，其余每行均有一处错误。

      Bad weather sometimes causes natural disasters. A snowstorm hitted
Beijing on Saturday, 28th December. The storm got bad in the afternoon.
Tom was on a farm and Uncle Li told him go home late. Li Ming
asked him to go to his house because Tom forgot to take his keys. So
Tom walked to the bus stop on his umbrella with Li Ming. The weather
was really terrible. They could only listen the wind. Snowstorm
continued to fall around them. Sudden they lost their umbrellas in the
wind and Tom nearly fell over. They could do nothing and walk slowly
in the storm. When they arrived in the bus stop, they could see many
people. They was really worried as there would be no bus soon.

1. _________
2. _________
3. _________
4. _________
5. _________
6. _________
7. _________
8. _________
9. _________
10. ________

多项选择题

十八届三中全会作出“使市场在资源配置中起决定性作用”的定位，有利于（）。

A、在全党全社会树立关于政府和市场关系的正确观念

B、有利于转变经济发展方式

C、有利于转变政府职能

D、有利于抑制消极腐败现象