Answer:
Explanation:
The vertex is halfway between the focus and the directrix:
((-7, 7) +(-7, 3))/2 = (-14, 10)/2 = (-7, 5) . . . . vertex coordinates
The value of p is the distance from the focus to the vertex:
7 -5 = 2 = p
In vertex form, the equation of the parabola is ...
y = 1/(4p)(x -h)^2 +k . . . . . . vertex (h, k)
y = 1/8(x +7)^2 +5