What is the directrix x=4y^2+12y+9 ?

The directrix x=4y^2+12y+9 is x=-1/16

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix x=4y^2+12y+9

directrix

x = 4 y^{2} + 12 y + 9

x = - \frac{1}{16}

Solution steps

Rewrite

x = 4 y^{2} + 12 y + 9

in the standard form

4 \cdot \frac{1}{16} (x - 0) = (y - (- \frac{3}{2}))^{2}

(h, k) = (0, - \frac{3}{2}), p = \frac{1}{16}

Parabola is symmetric around the x-axis and so the directrix is a line parallel to the y-axis, a distance

- p

from the center

(0, - \frac{3}{2})

x-coordinate

x = 0 - p

x = 0 - \frac{1}{16}

Refine

x = - \frac{1}{16}

7 x^{2} - 5 x + 9

- 8 x^{2} + 4 x

3 y + 4 x = - 2 x^{2} - 14

- x^{2} - 6 x - 13

3 x^{2} - 6 x + 9