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Math Help - Find all of the real and imaginary zeros for the polynomial function

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    [Solved]Find all of the real and imaginary zeros for the polynomial function

    Find all of the real and imaginary zeros for the polynomial function f(x)=x^3-7x^2+x-7 Answer is 7,-i,i How do I solve this to get to the answer
    Last edited by ToXic01; May 9th 2010 at 02:05 PM.
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by ToXic01 View Post
    Find all of the real and imaginary zeros for the polynomial function f(x)=x^3-7x^2+x-7 Answer is 7,-i,i How do I solve this to get to the answer
    Factor by grouping

    x^3 - 7x^2 + x - 7 = x^2(x - 7) + (x - 7)

    = (x - 7)(x^2 + 1)

    Now do you see how to get to the answer?
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    x^3-7x^2+x-7=x^2(x-7)+(x-7)=(x-7)(x^2+1)
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    Quote Originally Posted by Jhevon View Post
    Factor by grouping

    x^3 - 7x^2 + x - 7 = x^2(x - 7) + (x - 7)

    = (x - 7)(x^2 + 1)

    Now do you see how to get to the answer?
    so if i set this equal to zero i get the answer
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  5. #5
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    Quote Originally Posted by ToXic01 View Post
    so if i set this equal to zero i get the answer
    Yep make x^2 + 1=0 and x - 7=0
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