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Math Help - [SOLVED] Can't solve this with quotient rule!!

  1. #1
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    [SOLVED] Can't solve this with quotient rule!!

    I have this function Y=(X^2+2)/(x-1)
    and get this Y`=2x(x-1)-(x^2+2)/( x-1)^2.

    When I simplify to quadratic form I don’t get….x=1-sqrt3,1+sqrt3
    Can anyone help?
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  2. #2
    MHF Contributor harish21's Avatar
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    Quote Originally Posted by Neverquit View Post
    I have this function Y=(X^2+2)/(x-1)
    and get this Y`=2x(x-1)-(x^2+2)/( x-1)^2.

    When I simplify to quadratic form I don’t get….x=1-sqrt3,1+sqrt3
    Can anyone help?

    your differentiation looks good. What are you trying to do after that? ?
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  3. #3
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    Quote Originally Posted by harish21 View Post
    Did you mean solving for Y' = 0?
    Yes I tried to solve for x when f`=0. But I don't get x=1-sqrt3,1+sqrt3.
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  4. #4
    MHF Contributor chiph588@'s Avatar
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    Quote Originally Posted by Neverquit View Post
    I have this function Y=(X^2+2)/(x-1)
    and get this Y`=2x(x-1)-(x^2+2)/( x-1)^2.

    When I simplify to quadratic form I don’t get….x=1-sqrt3,1+sqrt3
    Can anyone help?
    I assume you're wanting to solve  y'=0

     y' = \frac{2x(x-1)-(x^2+2)}{(x-1)^2}=0\implies 2x(x-1)-(x^2+2)=0\implies x^2-2x-2=0

    Now just apply the quadratic formula and we're done.
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  5. #5
    MHF Contributor harish21's Avatar
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    As chip588 has stated above, you end up with

    x^2-2x-2=0

    This is a quadratic equation of the form ax^2+bx+c=0

    where, a = 1

    b = -2

    c= -2

    solve for x with this formula

    x = \frac {-b \pm \sqrt{b^{2}-4ac}}{2a}

    With this formula, you will get the answer you are looking for. Give it a shot!
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