Mark M. answered 10/05/18
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Retired math prof. Very extensive Precalculus tutoring experience.
Since the directrix is a vertical line, the axis of the parabola is horizontal and passes through the focus.
So, the axis is the horizontal line y = -4. The vertex lies on the axis and is halfway between the focus and directrix. So the vertex is (-3,-4). The focus is inside the arc of the parabola, so the parabola opens leftward.
Equation of parabola has the form: (y - (-4))2 = -4p(x - (-3))
(y + 4)2 = -4p(x + 3)
p is the distance from the focus to the vertex. So, p = 1.
Equation of parabola: (y+4)2 = -4(x+3).