What is the directrix (y+12)^2=9(x-9) ?

The directrix (y+12)^2=9(x-9) is x= 27/4

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directrix (y+12)^2=9(x-9)

directrix

(y + 12)^{2} = 9 (x - 9)

x = \frac{27}{4}

Solution steps

Rewrite

(y + 12)^{2} = 9 (x - 9)

in the standard form:

4 \cdot \frac{9}{4} (x - 9) = (y - (- 12))^{2}

(h, k) = (9, - 12), p = \frac{9}{4}

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

(9, - 12)

x-coordinate

x = 9 - p

x = 9 - \frac{9}{4}

Refine

x = \frac{27}{4}

0.5 x^{2} + 2

y = - 2 + x^{2}

y^{2} + 4 x + 1 = 0

5 x^{2} - 13 x - 6

x^{2} - 4 x - 5

What is the directrix (y+12)^2=9(x-9) ?
The directrix (y+12)^2=9(x-9) is x= 27/4