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Math Help - Domain Problem

  1. #1
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    Domain Problem

    What's the domain of G(t) = ln(t^4-1)?

    How did you get the answer, the answer in the book says that it's (-infinity, -1) union (1, infinity) but I don't really understand why.
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  2. #2
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    For x \in \left[ { - 1,1} \right]\quad  \Rightarrow \quad \ln \left( {x^4  - 1} \right) \mbox{ is meaningless!}
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  3. #3
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    Quote Originally Posted by Plato View Post
    For x \in \left[ { - 1,1} \right]\quad \Rightarrow \quad \ln \left( {x^4 - 1} \right) \mbox{ is meaningless!}
    What?
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  4. #4
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    Quote Originally Posted by dm10 View Post
    What?
    dn10, you have a very hard road of learning ahead of you if you truly want to understand this material.
    You should pay more attention to basic definitions.
    Of course, if you could care less then forget it.
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  5. #5
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    t^{4}-1=\left( t^{2}+1 \right)\left( t^{2}-1 \right)>0, this last 'cause logarithm is defined for numbers greater than zero. Hence, it remains to solve t^2-1>0 which gives the expected answer.
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