Mark M. answered 12/02/18
Retired math prof. Very extensive Precalculus tutoring experience.
The graph of g(x) = (x+3)2 - 5 is a parabola opening upward with vertex (-3,-5).
Since the graph fails the Horizontal Line test, the inverse will not be a function.
Restrict the domain to [-3, ∞), The restricted graph (the right half of the parabola) does satisfy the Horizontal Line Test. So, the inverse of the restricted function is also a function.