$\"\"$

The quadratic function is $\"\"$ . \ \ For this function a = $\"\"$ , so the graph opens down and the function has a maximum value. \ \ $\"\"$

The maximum value of the function is the y-coordinate of the vertex.

The $\"\"$ - coordinate of the vertex is $\"\"$ .

$\"\"$ (Substitute the values a = $\"\"$ and b = 6)

$\"\"$ (Simplify) \ \ The y-coordinate of the vertex by evaluating the function for $\"\"$ = 3. \ \

$\"\"$ (Original function)

$\"\"$ ( $\"\"$ = 3)

$\"\"$ or 8

The maximum value of the function is 8.

$\"\"$ \ \

The domain is all real numbers.

The range is all real numbers less than or equal to maximum value ,or $\"\"$ . \ \

$\"\"$ \ \

The function has maximum value.

The maximum value of the function is 8. \ \

The domain is all real numbers.

The range is $\"\"$ . \ \