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Homework Help: Rates of Change

  1. Jan 11, 2009 #1
    1. The problem statement, all variables and given/known data
    A medicine is administered to a patient. The amount, M, of the medicine in milligrams, in 1 mL of the patient's blood t hours after the injection is given by
    M(t) = -1/3t^2 + t where 0<=t<=3

    Find the rate of change of teh amount, M, 2 hours after the injection.


    2. Relevant equations



    3. The attempt at a solution

    No idea.
     
  2. jcsd
  3. Jan 11, 2009 #2
    Differentiate the equation and substitute t = 2 into M'(t).
     
  4. Jan 11, 2009 #3
    Elaborate please.
     
  5. Jan 11, 2009 #4
    You have M(t), what does M'(t) = ? Now plug in t into M'(t) i.e. evaluate M'(2)
     
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