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Math Help - radical equation help.

  1. #1
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    radical equation help.

    Hi guys, I was going through my book to refresh my calc 2 material and I saw this, anyone know how they got to the answer x=144/25? Thank you http://www3.wolframalpha.com/input/?i=0.2%3D(x%2B1)^(1%2F2)-x^(1%2F2)
    Last edited by skeeter; May 22nd 2012 at 05:00 PM.
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  2. #2
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    Re: radical equation help.

    \sqrt{x+1} - \sqrt{x} = \frac{1}{5}

    square both sides ...

    (x+1) - 2\sqrt{x(x+1)} + x = \frac{1}{25}

    combine like terms ...

    2x + \frac{24}{25} = 2\sqrt{x(x+1)}

    x + \frac{12}{25} = \sqrt{x(x+1)}

    square both sides again ...

    x^2 + \frac{24x}{25} + \frac{144}{625} = x(x+1)

    combine like terms ...

    \frac{144}{625} = \frac{x}{25}

    \frac{144}{25} = x

    btw ... this is not an exponential equation, it's a radical equation.
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  3. #3
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    Re: radical equation help.

    Thank you! I was using exponential e^lnx to solve it.. this is way easier
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