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Homework Help: Inverse and Composite Inverse Functions

  1. Apr 5, 2009 #1
    Hello :smile:

    I was wondering if someone could check my working and answers to these three homework questions. I've done the inverse functions in class, but not the composite inverse functions, if that's what they're called.

    1. The problem statement, all variables and given/known data
    http://img24.imageshack.us/img24/6035/question4t.jpg [Broken]

    2. Relevant equations
    http://img25.imageshack.us/img25/2204/equations4.jpg [Broken]

    3. The attempt at a solution
    http://img27.imageshack.us/img27/3402/attempt4a.jpg [Broken] http://img27.imageshack.us/img27/9500/attempt4b.jpg [Broken]

    I'd appreciate any feedback. Parts a and b are just like I've done in class. Where I've left them is where we ended them in class. Part c is just a guess. I don't know if there is a special rule or something like that.

    Thanks. :smile:
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Apr 5, 2009 #2
    It looks fine to me. Just a few tips, (x-2)/(-3)=(2-x)/3 , you generally don't want to leave negatives hanging at the bottom of fractions, and also [itex]f^{-1}h^{-1}=(hf)^{-1}[/itex] may help you in the future.
  4. Apr 6, 2009 #3
    Thanks for the reply. :smile:

    I didn't know about not leaving negatives at the bottom of fractions. I'll make sure I don't do that in future. :smile:

    I didn't know about the [itex](hf)^{-1}[/itex] bit either. I'm certain that will come up later in the course.

    I really appreciate this. You've put my mind at ease. :smile:

    Thanks again.
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