Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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?
    Isn't it more logical to do what's in the bracket first?

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


    User Avatar
    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?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook