請詳細教我計以下二條 :
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急 ! F4 Function
2011-10-24 5:35 pm
回答 (1)
2011-10-24 5:47 pm
✔ 最佳答案
13a) P = -2(x2 - 60x) - 800= -2(x2 - 60x + 900) - 800 + 1800
= -2(x - 30)2 + 1000
Hence P is max. when x = 30
b) Max. daily profit = 1000
14a) AB = 118 - x - (x + 2) = 116 - 2x
BC = x + 2
b) Area = (x + 2)(116 - 2x)
= -2x2 + 112x + 232
= -2(x2 - 56x) + 232
= -2(x2 - 56x + 784) + 232 + 1568
= -2(x - 28)2 + 1800
So when x = 28, the area will be max.
c) BC = 30 m, AB = 60 m, area = 1800 m2
參考: 原創答案
收錄日期: 2021-04-13 18:19:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111024000051KK00165