What is the directrix y=-5(x-4)^2+180 ?

The directrix y=-5(x-4)^2+180 is y= 3601/20

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directrix y=-5(x-4)^2+180

directrix

y = - 5 (x - 4)^{2} + 180

y = \frac{3601}{20}

Solution steps

Rewrite

y = - 5 (x - 4)^{2} + 180

in the standard form:

4 (- \frac{1}{20}) (y - 180) = (x - 4)^{2}

(h, k) = (4, 180), p = - \frac{1}{20}

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, 180)

y-coordinate

y = 180 - p

y = 180 - (- \frac{1}{20})

Refine

y = \frac{3601}{20}

x^{2} - 2 x + 2

- x^{2} - 3 x - 2

y = x^{2} + 7 x - 3

y^{2} + 12 x - 2 y - 11 = 0

\frac{x ^{2}}{9}

What is the directrix y=-5(x-4)^2+180 ?
The directrix y=-5(x-4)^2+180 is y= 3601/20