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Homework Help: Finding F'(5) from F(x) = f(g(x))

  1. Apr 19, 2010 #1
    1. The problem statement, all variables and given/known data

    If F(x) = f(g(x)), where f(-2) = 8, f'(-2) = 4, f'(5) = 3, g(5) = -2, and g'(5) = 6, find F'(5).

    2. Relevant equations

    F'(x) = f'(g(x)) * g'(x) - Chain Rule

    3. The attempt at a solution

    F'(x) = f'(g(x)) * g'(x)
    F'(5) = f'(g(5)) * g'(5)
    F'(5) = f'(-2) * 6
    F'(5) = 8 * 6
    F'(5) = 48

    The correct answer is 24:confused: which doesnt make sense.
     
  2. jcsd
  3. Apr 19, 2010 #2

    lanedance

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    Homework Helper

    f'(-2) = 4
     
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