Aparabola has a vertex at the origin. the focus of the parabola is located at (–2,0).which is the equation for the directrix related to the parabola? y = 2x = 2y = –2x = –2

If the vertex is at the origin and the focus is at (-2, 0), then this is a sideways-opening parabola; it opens to the left because the curve will always "hug" the focus.  The directrix is the same distance from the vertex as the focus is.  The focus is 2 units from the vertex, therefore, the directrix is 2 units from the vertex as well, but going the other way.  Since this is a sideways-opening parabola, the directrix is a vertical line.  The equation for that line then is x = 2.