Answer:
In factor form this is -1/4(x + 4)(x - 8).
Explanation:
It has a maximum so the coefficient of x^2 is negative and i also has 2 factors
( x + 4)(x - 8) , because of the 2 zeroes -4 and 8.
The equation is y = -a(x + 4)(x - 8) where a is some constant.
The vertex is at (2, 9) so substituting we have:
9 = -a(2 + 4)(2 - 8)
-36* -a = 9
a = 9/36 = 1/4.
So the function is -1/4(x + 4)(x - 8).