What is the directrix y=(x-4)^2 ?

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

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directrix y=(x-4)^2

directrix

y = (x - 4)^{2}

y = - \frac{1}{4}

Solution steps

Rewrite

y = (x - 4)^{2}

in the standard form:

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

(h, k) = (4, 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

(4, 0)

y-coordinate

y = 0 - p

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

Refine

y = - \frac{1}{4}

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

9 t - 2 t^{2}

x^{2} = 40 y

x^{2} - 6 x - y + 33 = 0

- 2 x^{2} + 4 x - 9