Question

What is the directrix of the parabola given by the equation x =

Answer 1

x = 1
y = 1
x = -1
y = -1

Answer 2

x=1 is correct

Answer 3

am i right?

Answer 4

The general equation for a parabola centred at origin with a horizontal axis is:
x=y^2/(4c)
where c is a constant.
Here you have x=-y^2/4, which makes c=-1.
The directrix is y=-c for a parabola centred at origin.

Answer 5

x=-c (for a parabola centred at origin with horizontal axis).
Yes, x=1 is the directrix.