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Math Help - domain problem

  1. #1
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    domain problem

    if the domain of f(x) is (-1,1) then what is the domain of f((x+1)/(x-1))?

    i don't even know how to start this problem. all i know is that x cannot be equal to 1.
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  2. #2
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    Quote Originally Posted by oblixps View Post
    if the domain of f(x) is (-1,1) then what is the domain of f((x+1)/(x-1))?

    i don't even know how to start this problem. all i know is that x cannot be equal to 1.
    The required domain will be the range of the function y = \frac{x + 1}{x - 1} over the interval -1 < x < 1. The best way of finding a range is to draw a graph.
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    What is this? A rational function?

    'Cause the way I find is that you take the bottom part and whatever turns out to be zero is what makes the domain...

    Did you need to rewrite it in a different notation?

    (-\infty, 1) \cup (1, \infty)
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    Quote Originally Posted by A Beautiful Mind View Post
    What is this? A rational function?

    'Cause the way I find is that you take the bottom part and whatever turns out to be zero is what makes the domain...

    Did you need to rewrite it in a different notation?

    (-\infty, 1) \cup (1, \infty)
    Read the question carefully. Your reply to it is irrelevant.
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  5. #5
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    Quote Originally Posted by oblixps View Post
    if the domain of f(x) is (-1,1) then what is the domain of f((x+1)/(x-1))?

    i don't even know how to start this problem. all i know is that x cannot be equal to 1.
    The domain of:

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

    will be the set of all real numbers x such that:

    y=\frac{x+1}{x-1} \in (-1,1)

    CB
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