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Math Help - Algeb

  1. #1
    Member srirahulan's Avatar
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    Lightbulb Algeb

    x^2+ax+1=0 the quadratic equation have roots (a) and (b) and also they are not equals to other.a+b+c=0 prove this and thorough this prove that x^2-ax+1has the roots (b+a) (c+a)
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    Re: Algeb

    Quote Originally Posted by srirahulan View Post
    x^2+ax+1=0 the quadratic equation have roots (a) and (b) and also they are not equals to other.a+b+c=0 prove this and thorough this prove that x^2-ax+1has the roots (b+a) (c+a)
    This question as stated is fundamentally flawed. That is unless a= \frac{i\sqrt2}{2}.
    Do you mean to have complex coefficients?
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  3. #3
    Member srirahulan's Avatar
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    Re: Algeb

    yes
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    Re: Algeb

    Quote Originally Posted by srirahulan View Post
    yes
    Well I gave you one of the roots, you find the other.
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    Re: Algeb

    Quote Originally Posted by srirahulan View Post
    x^2+ax+1=0 the quadratic equation have roots (a) and (b) and also they are not equals to other.a+b+c=0 prove this and thorough this prove that x^2-ax+1has the roots (b+a) (c+a)
    a and b are the two roots of the equation but what is "c"?

    Also you are using the same letter, a, to mean one of the roots and the coefficient of x. They cannot mean the same number:
    if (x- a)(x- b)= x^2- (a+b)x+ ab= x^2+ ax+ 1 then a+ b= a, so b= 0, and ab= 1 which is impossible if b= 0.
    Last edited by HallsofIvy; May 15th 2012 at 06:31 AM.
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    Re: Algeb

    Quote Originally Posted by HallsofIvy View Post
    a and b are the two roots of the equation but what is "c"?
    Also you are using the same letter, a, to mean one of the roots and the coefficient of x. They cannot mean the same number:
    if (x- a)(x- b)= x^2- (a+b)x+ ab= x^2+ ax+ 1 then a+ b= a, so b= 0, and ab= 1 which is impossible if b= 0.
    Yes indeed the a's are the same. Both a~\&~b are complex numbers.
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