A parabola opening up or down has vertex
(0,0) and passes through
(12,–18)
Write its equation in vertex form.
+36916 With vertex at 0,0 and including point 12, -18 it obviously opens downward (dome shaped)
Vertex form parabola
y = a (x-0)^2 + 0
y = a x^2 sub in 12 , -18
-18 = a (12^2)
a = -18/144 = - 1/8
y = -1/8 x^2
