What is the directrix y=-5x^2+118x+7 ?

The directrix y=-5x^2+118x+7 is y= 2813/4

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix y=-5x^2+118x+7

directrix

y = - 5 x^{2} + 118 x + 7

y = \frac{2813}{4}

Solution steps

Rewrite

y = - 5 x^{2} + 118 x + 7

in the standard form

4 (- \frac{1}{20}) (y - \frac{3516}{5}) = (x - \frac{59}{5})^{2}

(h, k) = (\frac{59}{5}, \frac{3516}{5}), 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

(\frac{59}{5}, \frac{3516}{5})

y-coordinate

y = \frac{3516}{5} - p

y = \frac{3516}{5} - (- \frac{1}{20})

Refine

y = \frac{2813}{4}

- x^{2}

x = - 8 y^{2}

y = 4 x^{2} + 23 x - 6

4 - X^{2}

x^{2} + 4 x - 4 y = 0

What is the directrix y=-5x^2+118x+7 ?
The directrix y=-5x^2+118x+7 is y= 2813/4