Question

what are the focus and directrix of the parabola with the equation y=1/16x^2

Answer 1

y=1/16x^2
multiplying both sides by 16 we get:
16y=x^2
The general form of a parabola is:
(x-h)^2=4p(y-k)
thus
4p=16
p=4
The parabola opens upwrd:
Focus: (h,k-p)
(0,0-4)
=(0,-4)
Directrix: y=-4