Question

HELP!!!!!

Answer 1

Solve for the x-max or h :\
$-b/(2a)=-8/(2*-2)=2=k$
plug it in to equation to get k:/
$y(2)=-2(2)^2+8(2)+3$
-8+16+3=11=k
$y=a(x-2)^2+11$
solve for a by pluging (0,0)
then a= -11/4
$y=-11/4(x-2)^2+11$