Answer:
a = 1/25
Step-by-step explanation:
The vertex form of the parabola is
y = a(x-h)^2 +k
where (h,k) is the vertex
y = a(x-2)^2 -4
We have a point on the parabola (-3,-3) so substitute this into the equation
-3 = a(-3-2)^2 -4
-3 = a(-5)^2 -4
Add 4 to each side
-3+4 = a(25) +4-4
1 = 25a
Divide each side by 25
1/25 = a
y = 1/25(x-2)^2 -4
