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Math Help - Calculate value of x

  1. #1
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    Calculate value of x

    Calculate value of x in (7x+1)^{\frac{1}{3}}+(-x^2+x+8)^{\frac{1}{3}}+(x^2-8x-1)^{\frac{1}{3}}=2
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  2. #2
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    In short, no solutions exist...
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  3. #3
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    How can I say.....

    Here is my process...

    Let (7x+1)^{\frac{1}{3}}=a

    (-x^2+x+8)^{\frac{1}{3}}=b

    (x^2-8x-1)^{\frac{1}{3}}=c

    So We Get a+b+c=a^3+b^3+c^3

    a(a^2-1)+b(b^2-1)+c(c^2-1)=0

    Now I am struck at that point.......
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  4. #4
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    zero is a solution, i just checked it by eye.
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  5. #5
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    plot using maple.

    x=-1,x=0,x=1 and x=9


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  6. #6
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    Quote Originally Posted by Krizalid View Post
    zero is a solution, i just checked it by eye.
    Interesting, Wolfram said "No Solutions Exist..."

    But you're right, 0 works...
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  7. #7
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    i think you can now understand me why i'm telling that you don't have to absolutely trust on wolfram everytime.
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