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Math Help - Focus of parabola

  1. #1
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    Focus of parabola

    x^2-ky+3=0 represents a parabola whose focus is in (0,2) find k
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  2. #2
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    Re: parabola

    Quote Originally Posted by prasum View Post
    x^2-ky+3=0 represents a parabola whose focus is in (0,2) find k
    T\left(\frac{-b}{2a},\frac{-D}{4a}\right)=(0,2)

    a=\frac{1}{k} , b =0 , c=\frac{3}{k} , D=b^2-4ac
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  3. #3
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    Re: parabola

    can yu tell me what will be the value of k 2 ,4,6 or 3
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  4. #4
    MHF Contributor Siron's Avatar
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    Re: parabola

    What have you tried? Princeps post tell's what you have to do, namely:
    The equation of the parabola is:
    y=\frac{x^2+3}{k}
    Therefore we can find k by solving the equation:
    \frac{-D}{4a}=2 \Rightarrow \frac{4ac-b^2}{4a}=2

    Proceed.
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