What is the directrix (y-3)^2=-12x ?

The directrix (y-3)^2=-12x is x=3

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directrix (y-3)^2=-12x

directrix

(y - 3)^{2} = - 12 x

x = 3

Solution steps

Rewrite

(y - 3)^{2} = - 12 x

in the standard form:

4 (- 3) (x - 0) = (y - 3)^{2}

(h, k) = (0, 3), p = - 3

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

- p

from the center

(0, 3)

x-coordinate

x = 0 - p

x = 0 - (- 3)

Refine

x = 3

(x - 2) = 3 (y - 5)^{2}

(x - 3)^{2} = 8 (y - 5)

y = \frac{x ^{2} x ^{1}}{x}

3 - x^{2}

y = 3 - x^{2}