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Math Help - Radical Equations

  1. #1
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    Radical Equations

    Can someone tell me how I can tell that sqrrt(x+4 = -5 has no solution without solving it?
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  2. #2
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    Can a positive square root have a negative value?
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  3. #3
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    Ok, I'm not sure, so if I'm wrong, someone please correct me.

    We use \sqrt{x} to represent the principal, positive square root of a number. The negative root is represented by - \sqrt{x}. The two square roots are represented together by  \pm \sqrt{x}.
    \sqrt{x+4} = -5 has no solution because you are referring to the positive root, which obviously can't be -5.
    Last edited by mr fantastic; April 9th 2009 at 02:54 PM. Reason: Removed inappropriate word
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  4. #4
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    Exactly: a positive square root cannot have a negative value.
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