Answer
$a=-3,b=6,c=1$
Work Step by Step
If the vertex of a graph is at (m,n) then the general formula for the quadratic function is $f(x)=a(x-m)^2+n$. According to the picture the vertex of the graph is at (1,4), hence the quadratic function becomes $f(x)=a(x-1)^2+4$. The point (-1,-8) is on the graph, hence if we plug in the values we get $-8=4a+4$, hence a=-3, hence $f(x)=-3(x-1)^2+4=-3x^2+6x+1$, thus $a=-3,b=6,c=1$
