$\"\"$

\

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 0 for h, 5 for k, 3 for x and 8 for y)

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

(Subtract 5 from each side)

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

(Divide each side by 9)

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

(Substitute $\"\"$ for a, 0 for h, and 5 for k)

\

$\"\"$

\

$\"\"$ $\"\"$

\

The vertex form of the parabola equation is $\"\"$ .