What is the directrix (x-3)^2-1 ?

The directrix (x-3)^2-1 is y=-5/4

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

directrix (x-3)^2-1

directrix

(x - 3)^{2} - 1

y = - \frac{5}{4}

Solution steps

Rewrite

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

in the standard form:

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

(h, k) = (3, - 1), 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

(3, - 1)

y-coordinate

y = - 1 - p

y = - 1 - \frac{1}{4}

Refine

y = - \frac{5}{4}

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

y = - 3 x^{2} + 5 x

x^{2} + 16 x + 8

(x - 3)^{2} - 4

(y + 1.5)^{2} = 4 (x - 2)