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

The directrix (x-h)^2=4p(y-k) is y=k-p

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix (x-h)^2=4p(y-k)

directrix

(x - h)^{2} = 4 p (y - k)

y = k - p

Solution steps

Rewrite

(x - h)^{2} = 4 p (y - k)

in the standard form:

4 p (y - k) = (x - h)^{2}

(h, k) = (h, k), p = p

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

(h, k)

y-coordinate

y = k - p

y = k - p

y^{2} + 8 x = 0

y = 2 x^{2} - 4 x + 15

x^{2} + 6 x + 8 y = 7

y = x^{2} - 6 x - 1

y^{2} + 6 y + 8 x + 25 = 0