作者YmemY (*＊米)
看板trans_math
标题Re: [考古] 99政大金融系
时间Wed Dec 1 01:21:02 2010
sales rate = 销售量 / 月 = dy/dx = x^2 exp{-x}
求最初到 x 月的累积销售量:
dy = ( x^2 exp{-x} )dx 积分此式，起点为零，终点为x
※ 引述《weiming (玮)》之铭言：
: A company's sales rate is x^2 exp{-x} million sales
: per month after x months.
: Find a formula for the total sales in the first x months.
: 请问有人知道这要怎麽算吗？谢谢大家
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1F：推 weiming:感谢 115.43.220.127 12/01 01:38