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

The directrix-x^2-2x-3 is y=-7/4

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix-x^2-2x-3

directrix

- x^{2} - 2 x - 3

y = - \frac{7}{4}

Solution steps

Rewrite

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

in the standard form

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

(h, k) = (- 1, - 2), 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

(- 1, - 2)

y-coordinate

y = - 2 - p

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

Refine

y = - \frac{7}{4}

- x^{2} - 2 x - 1

y + 3 x^{2} = 0

y^{2} - 8 x - 8 y + 24 = 0

y = + x^{2} - 4 x - 32

x^{2} + 2 x + 2