From the graph the vertex of the parabola is at
,
The parabola of the vertex is
,
, and
.
The point on the graph of the parabola
,
and
.
(Apply vertex form of the parabola equation:
)
Now we can find a value.
(Substitute
for h, 3 for k,
for x and 6 for y)




(Subtract 3 from each side)
\


(Substitute 3 for a,
for h, and 3 for k)


The vertex form of the parabola equation is
.