Question

Find the vertex, focus, directrix, and focal width of the parabola

Answer 1

-1/40x^2=y
@agent0smith

Answer 2

Multiply both sides by -40

\[\Large x^2 = -40y\]compare to standard form, where vertex is (0, 0)
\[\Large x^2 = 4p y\]
so 4p = -40, so p = -10

focus is (0, p)

directrix y = -p

focal width |4p|

Answer 3

so : Vertex: (0, 0); Focus: (0, -10); Directrix: y = 10; Focal width: 40