Respuesta :

Vertex = (4,8)

Passing through the origin = (0,0)

Vertex form:

y= a (x-h)^2+k

(h,k) is the vertex:

y= a (x-4)^2+8

Replace the (x,y ) by the origin coordinates

Solve for a

0= a (0-4)^2+8

-8 = a(-4)^2

-8 = a 16

-8/16 = a

-1/2 = a

y=-1/2 (x-4)^2+8