What is the directrix 7x^2-7x ?

The directrix 7x^2-7x is y=-25/14

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directrix 7x^2-7x

directrix

7 x^{2} - 7 x

y = - \frac{25}{14}

Solution steps

Rewrite

y = 7 x^{2} - 7 x

in the standard form

4 \cdot \frac{1}{28} (y - (- \frac{7}{4})) = (x - \frac{1}{2})^{2}

(h, k) = (\frac{1}{2}, - \frac{7}{4}), p = \frac{1}{28}

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{1}{2}, - \frac{7}{4})

y-coordinate

y = - \frac{7}{4} - p

y = - \frac{7}{4} - \frac{1}{28}

Refine

y = - \frac{25}{14}

y = + x^{2} + 8 x + 6

y = (x + 3) (x - 1)

(x + 3)^{2} = - 8 (y + 2)

y = 3 x^{2} + 4

y = 2 x^{2} - 8 x + 4