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Homework Help: Question From Test

  1. Dec 19, 2012 #1

    I have a question from a test that I wasn't sure about, so I guessed.

    The question is:

    f(3)= 5
    g(3)= -4
    f'(3)= 1.1
    g'(3)= .7

    What is fg'(3)

    Answer choices: a) .9 b) .4 c) -.9 d) -.4

    Does anyone know the answer? And how did you get it?

    Help would be much appreciated. Thanks!
    Last edited: Dec 19, 2012
  2. jcsd
  3. Dec 19, 2012 #2
    Do you mean (fg)'(3)?

    Also, homework help forum.

    Also (fg)'=fg'+gf'
    So just plug in what they gave.
  4. Dec 19, 2012 #3


    User Avatar

    Staff: Mentor

    You are required to show some effort at answering the question when posting schoolwork questions. Please use the hints from johnqwertyful and show your work...
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