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Homework Help: If (f o g)= 16x + 7 and g(x)= 2x - 1 , find f(x)

  1. Jul 30, 2011 #1
    1. The problem statement, all variables and given/known data

    If (f o g)= 16x + 7 and g(x)= 2x - 1 , find f(x)


    3. The attempt at a solution

    I haven't done a problem like this in awhile so I dont remember exactly what to do. I think you plug g(x) into (f o g) to get 32x - 9 but I'm not sure if that's correct.
    1. The problem statement, all variables and given/known data
     
  2. jcsd
  3. Jul 30, 2011 #2
    If this is correct, you should try f(g(x)) and see if you get what it was originally

    P.S. Notice your trying to get f(x)
     
  4. Jul 30, 2011 #3

    eumyang

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    Suppose that f(x) = Ax + B, a linear function. Given that, and that g(x) = 2x - 1, what is (f o g)(x)?
    (Ignore for a moment that (f o g)(x) was already given.)

    P.S. This should really be in the Precalculus subforum.
     
  5. Jul 31, 2011 #4

    SammyS

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    What is (f○g○g-1)(x) ?
     
  6. Aug 3, 2011 #5
    Wow, your good:wink: Didn't even think of that.
     
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