Chapter 11 - Review - Exercises - Page 833: 5

(a) Vertex: $V(0,0)$ Focus: $F(0,-2)$ Directrix: $y=2$ (b)

Equation of a parabola with vertical axis and vertex at $(h,k)$: $(x-h)^2=4p(y-k)$ $x^2+8y=0$ $x^2=-8y$ $(x-0)^2=-8(y-0)$ $h=0$ $k=0$ $4p=-8$ $p=-2$ Vertex: $V(h,k)=V(0,0)$ Focus: $F(0,p)=F(0,-2)$ Directrix: $y=−p=2$