Question

The focus of a parabola is located at (4,0), and the directrix is located at x = –4.

Answer 1

Answer: D. y2=16x

Step-by-step explanation:

Answer 2

The distance between the focus and directrix is, in this case, 8. Since the directrix is at x= something, the parabola opens sideways, and since the directrix is on the left, to the right. In which case, y^2=p(x), where p is 4 times distance of half of distance between directrix and focus, so the answer is y^2=16x