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Math Help - Functions F(x)

  1. #1
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    Exclamation Functions F(x)

    Two functions are defined as





    and

    Find ?

    Find ?

    Find ?

    What do I need to do?
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  2. #2
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    Re: Functions F(x)

    Quote Originally Posted by leonm92 View Post
    What do I need to do?
    For starters, find f(-5). I assume fg(-4) means f(g(-4)). Usually one writes (f\circ g)(4) where \circ is the operation of function composition, or, skipping \circ, (fg)(4) or f(g(-4)) instead of fg(-4).
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  3. #3
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    Re: Functions F(x)

    ok thank you. what if theres a function like f^-1 (-2)
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  4. #4
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    Re: Functions F(x)

    f^{-1} is a function inverse to f. Note that (not necessarily in your problem, but in general) for some y there may be several different x such that f(x) = y. In this case, it is not clear to which of those x the inverse function f^{-1} should map y. Therefore, the concept of inverse function is unambiguous only if the original function is injective.
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  5. #5
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    Re: Functions F(x)

    let's say you want to find f(-5). to do that, compute:

    (2(-5) + 9)/((-4)(-5) 5) = ?
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