Answer: Choice B
y = (x+3)^2 - 1
==================================================
Recall that vertex form is y = a(x-h)^2 + k with the vertex being (h,k)
From the given graph, it shows that (h,k) = (-3,1) is the vertex. So we plug this pair of values into the general function above to get
y = a(x-h)^2 + k
y = 1(x-(-3))^2 + (-1)
y = (x+3)^2 - 1
which is the final answer
note: a = 1 is the case for all four answer choices, so we don't have to worry about the value of 'a'
