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Math Help - Substituting f(x)

  1. #1
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    Substituting f(x)

    I know this is really basic why does

    <br />
f(2)=-4{x}^{-1}

    equal

    <br />
-2

    and not

    -8
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  2. #2
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    Quote Originally Posted by Envy View Post
    I know this is really basic why does

    <br />
f(2)=-4{x}^{-1}

    equal

    <br />
-2

    and not

    -8
    Your question does not make any sense.


    Are you asking:

    If f(x) = -4x^{-1} what does f(2) equal?


    Let x = 2.


    You would have f(2) = -4(2)^{-1}

     = -4\left(\frac{1}{2}\right)

     = -2.
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  3. #3
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    Substituting 2 into the equation



    -4 * ( 2 to the power of -1 )

    2 to the power of -1 is the same as 1 / 2

    so -4 * 1/2 = -2 and not -8
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