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Math Help - Error in Spivak inequality answer?

  1. #1
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    Error in Spivak inequality answer?

    Hello,

    I've just started Spivak's Calculus and got stuck with Problem 4 x in Chapter 1 (3rd edn):

    Find all numbers x for which (x-\sqrt[3]{2})(x+5)(x-3) > 0

    From inspection (based on the three obvious roots) I got: x>3 or -5 < x < \sqrt[3]{2}

    Spivak's answer is: x > \sqrt{2} or x < \sqrt[3]{2}. I don't understand how Spivak got that answer? Is there an error in the answer book, or am I completely lost?

    Thanks!
    Last edited by Jodles; August 12th 2012 at 11:19 AM. Reason: Tex fix
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  2. #2
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    Re: Error in Spivak inequality answer?

    Quote Originally Posted by Jodles View Post
    Hello,

    I've just started Spivak's Calculus and got stuck with Problem 4 x in Chapter 1 (3rd edn):

    Find all numbers x for which (x-\sqrt[3]{2})(x+5)(x-3) > 0

    From inspection (based on the three obvious roots) I got: x>3 or -5 < x < \sqrt[3]{2}

    Spivak's answer is: x > \sqrt{2} or x < \sqrt[3]{2}. I don't understand how Spivak got that answer? Is there an error in the answer book, or am I completely lost?
    Your answer is correct.
    Thanks from Jodles
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  3. #3
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    Re: Error in Spivak inequality answer?

    Thank you, Plato!
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