已知圆C的方程为x2+y2+(m-2)x+(m+1)y+m-2=0,根据下列条件

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问题:

已知圆C的方程为x2+y2+(m-2)x+(m+1)y+m-2=0,根据下列条件确定实数m的取值,并写出相应的圆心坐标和半径。

⑴圆的面积最小;

⑵圆心距离坐标原点最近。

考点:圆的标准方程与一般方程
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美国PSI指数的评价因子不包含()

A.SO2

B.NO2

C.CO

D.CO2

E.O3

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C

A car needs gas to run as your body needs food to work for you. Eating the right kinds of food is very important. A good eating habit can help your body grow strong if you take care of what you eat.

There are four main food groups altogether. The dairy group has food like milk, cheese and sour milk. The other three groups are the meat and fish group, the fruit and vegetable group, and the bread and rice group. Each meal should have at least one food from all four main groups. With all of these foods together, you will be given enough energy during the day.

It is easy to get into bad eating habits. You may eat your breakfast in a hurry to get to school on time or you may not have time for a good lunch. It may be easier to eat fish and chips for your supper all the time. But you will find yourself tired and you will not be able to think quickly.

Watching what you eat will help keep your body healthy and strong. It is also good to take some exercise. It will help you eat more if you take a walk or play games in the open air. Having good eating habits with some exercise is the key to your health.

69. According to the passage, which of the following diets do you think is the best one?

A. Eggs, tomatoes and chicken.          B. Milk, bread, cabbages and beef.

C. Corn, fish, ice cream and pork.        D. Rice, beancurd, fish and chicken.

70. In this passage the writer mainly tells us that ______.

A. every person needs food to grow well

B. taking exercise can keep your body strong

C. the right kind of food with exercise will keep you healthy

D. enough energy helps people think more quickly

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轮式起重机起吊重物的荷载不得超过允许负荷的()%时,可缓慢行驶。

A.70

B.75

C.80

D.85

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相位表法即用便携式伏安相位表测量相位,绘制向量图、进行接线分析

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以外购两种以上酒精生产的白酒,从高确定税率征税。

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