Question

Find the equation of the directrix
of the parabola , if
its focus is at
(0-3) and vertex is at origin.

Answer 1

Explanation:

Here, focus S(0,-3) and directrix y=3 are at same distance from origin is vertex of the parabola and parabola opens downwards.

So, we consider equation x2=-4ay.

So, equation of parabola is y2=-12x.

So, directrix is y=-2.