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Homework Help: Order of transforming a function

  1. Nov 28, 2005 #1
    Q. y= f(-x-4)

    Hi, I was wondering why I must factor out -1 to make the function y=(-1(x+4)).
    I tried to look in the texbook but it doesn't say why I have to do it that way..

    Also when transforming a fuction, why should I do it from left to right?
    y=a(f(x-b))+d
    Isn't it more logical to do what's in the bracket first?

    Thank you.
     
  2. jcsd
  3. Nov 28, 2005 #2

    HallsofIvy

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    Science Advisor

    If you specifically mean that f(x)= 1/x you should say so at the start!
    If f(x)= 1/x then f(-x-4)=1/(-x-4) of course. You don't HAVE to write that as 1/(-(x+4))= -1/(x+4) but it is a lot simpler to write and work with that way.

    And what, exactly, is in the bracket? f(x-b)? Since you haven't told us what f is, I don't know HOW to do that. Exactly WHAT do you mean by
    y= a(f(x-b))+ d?
     
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