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Math Help - equation 1

  1. #1
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    equation 1

     <br /> <br />
\begin{array}{l}<br />
 solve\;in\;R \\ <br />
  \\ <br />
 x^4  - 2x^2  - 400x = 9999 \\ <br />
 \end{array}<br /> <br />
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  2. #2
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    Bring everything to one side

    x^4 - 2x^2 - 400x - 9999 = 0.

    Now work out the factors (positive and negative) of 9999.

    Substitute each of these factors into the polynomial.

    By the factor theorem, if any of these factors (call it a) makes the polynomial  = 0, then x - a is a factor.
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  3. #3
    MHF Contributor Unknown008's Avatar
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    Solve in R? Do you mean for the real solutions?

    Anyway, rearrange;

    x^4 - 2x^2 - 400x - 9999= 0

    Then, I'll use the factor theorem.

    Let f(x) = x^4 - 2x^2 - 400x - 9999

    By trial and error, find the values of x that are factors of 9999 that make f(x) = 0. Those are the factors of your equation.

    Use long division or inspection to divide f(x) by their factors to get other factors, until you get a quadratic which is more easily factorised.

    If it cannot be solved, then the values you got for f(x) = 0 are the only solutions.

    EDIT: Woops, too late... I was making sure there were solutions =S
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