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Math Help - Restrictions on variables

  1. #1
    Junior Member
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    Restrictions on variables

    For the question (n^3+2n^2-n-2) / (n^2-1)
    i found the answer to be n+2 using long division

    in the book the restrictions on the variable says +or - 1
    i think it is just +1
    could someone explain to me why the book put this (assuming that it is correct of course)
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  2. #2
    Senior Member slevvio's Avatar
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    Look at the denominator  n^{2}-1 .

    If n = +1 then  (1)^{2}-1 = 1 - 1 = 0 .
    If n = -1 then  (-1)^{2} -1 = 1 - 1 = 0 .

    The denominator cannot equal zero and so n cannot equal +1 or -1.
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  3. #3
    Junior Member
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    thanks ....i totally missed that the n was squared lol
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