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Math Help - If a function is continuous

  1. #1
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    If a function is continuous

    Hello i got problem with nr 22. Because x^(1/3) is delfined for possitive and negative so idk what its domain is.
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  2. #2
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    Re: If a function is continuous

    Quote Originally Posted by Petrus View Post
    Hello i got problem with nr 22. Because x^(1/3) is delfined for possitive and negative so idk what its domain is.

    The domain of \sqrt[3]x(x^3+1) is all real numbers.

    Both factors are continuous functions.
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  3. #3
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    Re: If a function is continuous

    if  \sqrt[3]{a} = x then  a = x^3 or a solution must exist for  x^3 - a = 0 Now what do you know about cubic roots? It has 3 roots, and complex roots only come in pairs when you have real coefficients, so u could either have 2 complex roots and 1 real root or 3 real roots. Which means you always have atleast one real root, so the domain is all real numbers.
    Last edited by jakncoke; February 8th 2013 at 06:44 AM.
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