What is the directrix (9x^2)/2 ?

The directrix (9x^2)/2 is y=-1/18

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix (9x^2)/2

directrix

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

y = - \frac{1}{18}

Solution steps

Rewrite

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

in the standard form:

4 \cdot \frac{1}{18} (y - 0) = (x - 0)^{2}

(h, k) = (0, 0), p = \frac{1}{18}

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

(0, 0)

y-coordinate

y = 0 - p

y = 0 - \frac{1}{18}

Refine

y = - \frac{1}{18}

2 x^{2} + 8 x + 13

2 x^{2} - 4 x + 9

3 x^{2} - 31 x + 56 - (x - 8)

y = - 2.1 x^{2} + 410 x - 1340

y = x^{2} - 10000 x - 24000000