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Math Help - Linear factors of polynomial

  1. #1
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    Linear factors of polynomial

    Find the linear factors of 6 + 5x - 2x^2 - x^3
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  2. #2
    Senior Member Peritus's Avatar
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    first look here:

    Rational root theorem - Wikipedia, the free encyclopedia

    now armed with this new knowledge we can see that x = -1 is a possible root of the polynomial, and after substituting it in the polynomial we see that it's indeed a root, now all we have to do is reduce the polynomial to second degree by long division
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  3. #3
    Grand Panjandrum
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    Quote Originally Posted by nerdzor View Post
    Find the linear factors of 6 + 5x - 2x^2 - x^3
    The rational root theorem tell us that if this has a linear factor with rational
    coeficients it is one of: (x \pm 1),\ (x \pm 2),\ (x \pm 3),\ (x \pm 6).

    Working our way through these shows that (x+1) is in fact a factor and:


    6 + 5x - 2x^2 - x^3=(x+1)(-x^2-x+6)

    and the quadratic you can deal with using the quadratic formula.

    RonL
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