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

The directrix y=-2x^2-3 is y=-23/8

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directrix y=-2x^2-3

directrix

y = - 2 x^{2} - 3

y = - \frac{23}{8}

Solution steps

Rewrite

y = - 2 x^{2} - 3

in the standard form:

4 (- \frac{1}{8}) (y - (- 3)) = (x - 0)^{2}

(h, k) = (0, - 3), p = - \frac{1}{8}

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

(0, - 3)

y-coordinate

y = - 3 - p

y = - 3 - (- \frac{1}{8})

Refine

y = - \frac{23}{8}

x^{2} - 2 x - 4 y + 17 = 0

x^{2} - 12 y - 6 x + 5 = 0

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

3 x^{2} - 4 x - 2

x^{2} - 5 x - 6