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Inverse functions

  1. Sep 4, 2011 #1
    Problem: If g(x) = 3 + x + e^x find Inverse of g at 4

    My work:

    4 = 3 + x + e^x
    1 = x + e^x

    This is where I stop... I can look at it and see that x = 0
    But I dont know how to find the solution algebraically.....
  2. jcsd
  3. Sep 4, 2011 #2


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    Homework Helper

    You can't find the solution algebraically, you'll need to use numerical methods.
  4. Sep 4, 2011 #3


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    Science Advisor

    On the one set of axes draw a sketch of y=e^x and y=1-x and see that there's only the one solution. So your initial guess is it.

    There is no algebraic solution in terms of elementary functions. So your "look at it" method is as good as any.
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