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Math Help - Range and Domain

  1. #1
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    Unhappy Range and Domain

    I need a little help here-not sure if I got it right:
    f(x)= 2/x+1, g(x)= x/x+1
    domain of f is {x is part of a set where x >0} and domain of g is {x is part of a set where x is greater than or equal to 0} [0, infinity)U(0,infinity).
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  2. #2
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    OK

    Both of the functions are rational functions... in other words, of the form

    f(x) = \frac{g(x)}{h(x)}, where g(x) and h(x) are continuous functions of x.

    f(x) is also continuous at all points except where the denominator (h(x))=0.

    So where does the denominator equal 0? In both cases, where x = -1.

    So the domain of each function is \mathbf{R}\backslash \{-1\}.
    Last edited by Prove It; September 28th 2008 at 05:34 PM.
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  3. #3
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    Range and domain

    The first one...
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  4. #4
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    Sorry for the double post, didn't realise I edited the first one instead of adding a new one.


    OK

    Both of the functions are rational functions... in other words, of the form

    , where and are continuous functions of .

    is also continuous at all points except where the denominator .

    So where does the denominator equal 0? In both cases, where .

    So the domain of each function is \mathbf{R} \backslash \{-1\}.
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  5. #5
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    Unhappy range and domain

    wow..so i wasn't even close, huh?
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  6. #6
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    Quote Originally Posted by Vivianp View Post
    wow..so i wasn't even close, huh?
    No, but that's ok, that's what we're here for.

    Just always have in the back of your mind "You can't divide by 0" and you'll be fine
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