Answers:
Vertex is (-1,0)
Axis of symmetry is x = -1
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Step-by-step explanation:
F(x) = 3(x+1)^2 
is the same as 
y = 3(x-(-1))^2 + 0 
which is in the form 
y = a(x-h)^2 + k
We can see that
a = 3
h = -1
k = 0
Therefore the vertex is (h,k) = (-1,0)
The axis of symmetry is x = h = -1 which is the equation x = -1
The axis of symmetry in this case is a vertical line through the vertex.