$\"\"$

The form of quadratic function $\"\"$ with vertex $\"\"$ .

If a < 0, the function "f " has a maximum at $\"\"$ .

The maximum value $\"\"$ .

The function $\"\"$ and its maximum value 48.

Compare the function with $\"\"$ .

$\"\"$ .

Since a < 0, the function has a maximum at $\"\"$ .

Substitute the values of $\"\"$ in $\"\"$ .

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

The maximum value $\"\"$ .

$\"\"$

$\"\"$ \ \

$\"\"$ .

$\"\"$

The values of $\"\"$ .