Question

Let R = {0,1,2,3}be the range of h(x)= x-7. The domain of h is?

Answer 1

h(x)=x-7
h^-1(x)=x+7

From
range of h(x) = domain of h^-1(x)
and
domain of h(x) = range of h^-1(x)

We conclude that the domain of h(x) is the same as the range of
h^-1(x)=x+7
where the domain of h^-1(x) is {0,1,2,3}.
For example:
h^-1(0)=0+7=7
...
domain of h(x) is therefore {7,...}