How do I find the directrix of the parabola y=2x^2?

Apr 2, 2018

$y + \frac{1}{8} = 0 , \mathmr{and} , 8 y + 1 = 0$.

Explanation:

The eqn. of the directrix of the parabola ${x}^{2} = 4 b y$ is given

by, $y + b = 0$.

As, in our Problem $b = \frac{1}{8}$, the desired eqn. is,

$y + \frac{1}{8} = 0 , \mathmr{and} , 8 y + 1 = 0$.