What is the directrix y=-3x^2+6x-1 ?

The directrix y=-3x^2+6x-1 is y= 25/12

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directrix y=-3x^2+6x-1

directrix

y = - 3 x^{2} + 6 x - 1

y = \frac{25}{12}

Solution steps

Rewrite

y = - 3 x^{2} + 6 x - 1

in the standard form

4 (- \frac{1}{12}) (y - 2) = (x - 1)^{2}

(h, k) = (1, 2), p = - \frac{1}{12}

Parabola is symmetric around the y-axis and so the directrix is a line parallel to the x-axis, a distance

- p

from the center

(1, 2)

y-coordinate

y = 2 - p

y = 2 - (- \frac{1}{12})

Refine

y = \frac{25}{12}

X^{2} - 5 X - 24

y = 2 x^{2} + 5 x + 2

y^{2} + 4 y + 8 x - 12 = 0

4 x^{2} - 8 x + 2 y = 5

88 x - 16 x^{2} - 112