Question 1081914
The coordinates of the focus are (h, k + (1/4a)), where h=3, and k+(1/4a)=-7
k+(1/4a)=-7
The vertex is half way between the focus and the directrix, or at (3, -5.5), so k=-5.5
-5.5+(1/4a)=-7
(1/4a)=-1.5
1=-6a
a=(-1/6)
The equation is y=(-1/6)(x-3)^2-5.5
or (y+5.5)=(-1/6)(x-3)^2
or -6(y+5.5)=(x-3)^2