What is the directrix 3x^2+6x-45 ?

The directrix 3x^2+6x-45 is y=-577/12

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix 3x^2+6x-45

directrix

3 x^{2} + 6 x - 45

y = - \frac{577}{12}

Solution steps

Rewrite

y = 3 x^{2} + 6 x - 45

in the standard form

4 \cdot \frac{1}{12} (y - (- 48)) = (x - (- 1))^{2}

(h, k) = (- 1, - 48), p = \frac{1}{12}

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, - 48)

y-coordinate

y = - 48 - p

y = - 48 - \frac{1}{12}

Refine

y = - \frac{577}{12}

- x^{2} - 4 x - 3

y^{2} = - 7 x

x = y^{2} - 4

y = x^{2} + 5 x - 14

(x + 1)^{2} = - 3 (y - 6)