What is the directrix-x^2-4x-4 ?

The directrix-x^2-4x-4 is y= 1/4

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directrix-x^2-4x-4

directrix

- x^{2} - 4 x - 4

y = \frac{1}{4}

Solution steps

Rewrite

y = - x^{2} - 4 x - 4

in the standard form

4 (- \frac{1}{4}) (y - 0) = (x - (- 2))^{2}

(h, k) = (- 2, 0), p = - \frac{1}{4}

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

(- 2, 0)

y-coordinate

y = 0 - p

y = 0 - (- \frac{1}{4})

Refine

y = \frac{1}{4}

y = x^{2} - 8 x

- x^{2} - 4 x + 2

y = x^{2} - 6 x

y^{2} + 4 x = 0

y^{2} = \frac{- 16}{5} x