Question 1001325
48y= -x^2
y= -(1/48)x^2.  This is a parabola that opens downward, is wide due to the small coefficient of x, and is symmetrical around the y-axis.  The focus will be negative, the directrix positive.
(y-0)^2= (-1/48)(x-0)^2
4p(y-k)=(x-h)^2
y^2=(-1/48)(x-0)^2
-48y^2=(x-0)^2
4p=-48
p=-12
The focus is 12 units below the vertex, which is at (0,0).  That would be at (0,-12)
The axis of symmetry is the y-axis, or x=0.
The directrix is 12 units above the vertex or y=12
{{{graph(300,200,-40,40,-20,20,(-1/48)x^2,12)}}}
Check a point.  At x=6, y=-36/48 or -3/4.  The distance of the point from the directrix is 12.75 units.
The distance of that point (6,-0.75) from the focus is sqrt (6^2+11.25^2)=sqrt(162.5625)=12.75 units