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Log Rules

  1. May 1, 2014 #1
    1. The problem statement, all variables and given/known data

    Got to part of a problem where I have exp(-3ln(x)) and I am confused as to whether the next step is:

    a) exp(ln(x^-3)) = x^-3

    or

    b) exp(-ln(x^3)) = -x^3


    I think the correct step is (a) but not certain, any help would be great :)
     
  2. jcsd
  3. May 1, 2014 #2

    SammyS

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    Yes (a) is the correct result.

    For (b):

    exp(-ln(x^3)) = ##\displaystyle \frac{1}{e^{\ln (x^3)}}\ ## → ##\displaystyle \ \frac{1}{x^3} \ .##
     
  4. May 2, 2014 #3

    vela

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    Here it appears you're saying ##e^{-a} = -e^a##, that you can simply pull the minus sign out front, which you probably know isn't correct.
     
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