Find the vertex, focus, and directrix pf the given parabola y^2 = −4(x − 3)?

I'm just lost, can do other similar problems but this one is just impossible for me.

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  • Hemant
    Lv 7
    9 years ago
    Best Answer

    The given parabola is : y² = -4 ( x - 3 ).

    ∴ Y² = 4aX, ................................................ (1)

    ... where :

    ... X = x - 3, Y = y, 4a = -4, i.e., a = -1

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    ∴ Vertex ≡ ( X = 0, Y = 0 ) ≡ ( x-3 = 0, y = 0 ) ≡ ( 3, 0 )

    ... Focus ≡ ( X = a, Y = 0 ) ≡ ( x-3 = (-1), y = 0 ) ≡ ( 2, 0 )

    ... Directrix : X = -a ∴ x-3 = -(-1) ∴ x = 4

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    Happy To Help !

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  • 9 years ago

    y=x^2+4x+3 3x^2

    =x^2+3x+1x+3 = 3*1 = 3 and 3+1=4

    =x(x+3) +1 (x+3)

    =(x+1) (x+3)

    i think this information helpful for you.

    bj ..

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