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Homework Help: Significance of the second derivative

  1. Oct 25, 2011 #1
    1. The problem statement, all variables and given/known data

    Let y = s(t) represent the number of students who have contracted measles at time t (days). Give an interpretation for each condition:

    e) s' = 0, s" > 0

    3. The attempt at a solution

    This seems counterintuitive to me, to think that the second derivative is also not zero. In the context of the problem, what does this mean? So far I've said that no students are contracting measles anymore, but I don't know where s" fits in here.
  2. jcsd
  3. Oct 25, 2011 #2


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    Homework Helper

    well for a start what does s'=0 tells you about the problem?

    its not counter-intuitive to have s" non-zero whilst s'=0. If s" is non-zero it simply means the value of s' is changing

    HINT: if you know s'=0, and s" is non zero, then s' must be changing from either (+ve to -ve) or (-ve to +ve)
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