问题
问答题
求抛物线y2=2x与直线y=x-4所围图形的面积．
答案
参考答案：如图，取y为积分变量．
[*]
联立方程[*]．得交点纵坐标为y1=-2，y2=4．故所求面积为：
[*]
解析：
[分析]： 求平面图形的面积关键是画出平面图形并确定积分变量和积分上、下限．
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求抛物线y2=2x与直线y=x-4所围图形的面积．
参考答案：如图，取y为积分变量．
[*]
联立方程[*]．得交点纵坐标为y1=-2，y2=4．故所求面积为：
[*]
解析：
[分析]： 求平面图形的面积关键是画出平面图形并确定积分变量和积分上、下限．
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| One Friday morning, Bill 1 up late. He gets 2 the classroom. Mr Gar, his maths teacher says, "You are late again. Now how many times are you late this week?" "Three times." says Bill. "Why are you late again? Why don't you get up 3 ?" "It isn't my fault, Mr Gao. The TV play is over 4 eleven." answers Bill. "Now 5 me look 6 your homework," says the teacher. "I'm sorry, I can't do it," says Bill. " 7 can't you do it?" asks the teacher. "Because the first part of the homework is 8 easy. I don't think I 9 to do it. The second part is too difficult 10 me to do it. I can't work it out. So I don't do it." answers Bill. | |||
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