Answers:
Vertex is (-1,0)
Axis of symmetry is x = -1
============================================
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.