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Math Help - find the formula for the function

  1. #1
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    find the formula for the function

    f(x)= x^2+1 g(x)=1/(x-3)

    f(g(x))

    so (1/(x-3))^2 +1

    and from there i am lost on this problem.

    thanks
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  2. #2
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    Quote Originally Posted by valvan View Post
    f(x)= x^2+1 g(x)=1/(x-3)

    f(g(x))

    so (1/(x-3))^2 +1

    and from there i am lost on this problem.

    thanks
    Your working out is correct.

    You also don't really need to go any further, unless you are asked to write it down in a different way...

    f(g(x))=\left(\frac{1}{x - 3}\right)^2 + 1

     = \frac{1}{(x - 3)^2} + 1

     = \frac{1}{x^2 - 6x + 9} + \frac{x^2 - 6x + 9}{x^2 - 6x + 9}

     = \frac{x^2 - 6x + 10}{x^2 - 6x + 9}.


    This is about as far as you can go, but like I said, what you had so far is also correct.
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  3. #3
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    ok thanks, just got confused over how far i should go, this clears it up for me.
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