推 weiming:感謝 115.43.220.127 12/01 01:38
sales rate = 銷售量 / 月 = dy/dx = x^2 exp{-x}
求最初到 x 月的累積銷售量:
dy = ( x^2 exp{-x} )dx 積分此式，起點為零，終點為x
※ 引述《weiming (瑋)》之銘言：
: 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.
: 請問有人知道這要怎麼算嗎？謝謝大家
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 218.170.48.12