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Math Help - Using complex roots to find all zeros of a function.

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    Using complex roots to find all zeros of a function.

    2x^3+3x^2+50x+75

    Given: Zero = 5i
    so logically -5i is a zero.

    then I multiply the two roots and get 25.

    then divide Polynomial by 25?
    If so, how?
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  2. #2
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    Quote Originally Posted by Isimbot View Post
    2x^3+3x^2+50x+75

    Given: Zero = 5i
    so logically -5i is a zero.

    then I multiply the two roots and get 25.

    then divide Polynomial by 25?
    If so, how?
    (x-5i)(x+5i) = x^2+25

    \frac{2x^3+3x^2+50x+75}{x^2+25}

    do the long division to find the last linear factor
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