Question

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

Answer 1

`y+1/8=0, or, 8y+1=0`.

Explanation:

The eqn. of the directrix of the parabola `x^2=4by` is given

by, `y+b=0`.

As, in our Problem `b=1/8`, the desired eqn. is,

`y+1/8=0, or, 8y+1=0`.