State whether the domain of the function must be restricted to ensure that its inverse is a functionGive an appropriate restriction where needed. (a - c).(for the ones below)

Question

A.f(x) = (x - 5)^2 + 3 

B.g(x) = sqrt(2x + 4) 

C.h(x) = 4x^2 + 20x + 25 

Answer 1

A parabola cannot ever have an inverse unless only the portion on one side or the other of the vertex is included (domain restricted!).

The sqrt function is already domain restricted so positive values (in this case x greater than or equal to -2.

But with that restriction, there is an inverse.