[微分] 應用問題x2

[s1990716 (小婷)]

1.Marginal Profit
  When the price of a glass of lemonade at a lemonade stand was $1.75,
  400 glasses were sold. When the price was lowered to $1.50, 500 glasses
  were sold. Assume that the demand function is linear and that the variable
  and fixed cost are $0.10 and $25,respectively.

  Find the profit P as a function of x,the number of glasses of lemonade sold.


2.Depreciation
  The value V of a machine t years after it is purchased is inversely
  proportional to the square root of t+1. The initial value of the machine is
  $10,000.

  a.Write V as a function of t
  b.Find the rate of depreciation when t=1

  煩請各位高手解惑~~~

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◆ From: 122.116.127.139
→ matmoki:第一題有沒有漏打 標題寫MP 題目問π @@
→ matmoki:問π的話 就求出需求 再帶入TR-TC
→ matmoki:第二題應該是 (dv/dt)=-(t+1) 用分離變數
→ matmoki:冏 沒看到square root
→ matmoki:第二題好像是我想太多了 應該v=c/√(t+1)
→ matmoki:t=0帶入得C  sorry 最近微方寫多了 誤看XD
→ s1990716:我題目沒漏打~謝謝M大!!