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Homework Help: Partial Derivatives Again

  1. Mar 1, 2009 #1
    1. The problem statement, all variables and given/known data
    (e^0.16)/(1+e^-0.3y)
    I am suppose to find the fy
    of this

    2. Relevant equations
    A bit trickier than the last prob i posted


    3. The attempt at a solution
    What I did:
    Since (e^0.16) is a constant, I left it just like that and took the derivative of e(-0.3y)

    my outcome: (e^-0.16)/(-0.3e^-0.3y)
     
  2. jcsd
  3. Mar 1, 2009 #2
    You can't just take the derivative of the bottom and leave it like that. That's equivalent to saying that the derivative of 1/f is 1/f', which is false. First of all, find the derivative of 1/x. Now use substitution and the chain rule.
     
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