Question

Can the domain and range be the same?

Answer 1

Yes. See explanation.

Explanation:

Yes.

The best examplaes may be polynomial functions.

If we consider a function like `f(x)=x^3`, we can say it is defined for all real numbers (i.e. the domain is `D=RR`).

Its range is also `RR`, because for any real `y` we can say, that the value is reached in a point `x=root(3)(y)`