Question 1051140
Start from standard form.


{{{f(x)=a(x-h)^2+k}}} has vertex  (h,k).


{{{f(x)=a(x+3)^2-1}}}, filling for your given vertex.


{{{a(x+3)^2=f(x)+1}}}

{{{a=(f(x)+1)/(x+3)^2}}}

{{{a=(3+1)/(-5+3)^2}}}, filling for the other given point.