Question

Which of the following could be an example of a function with a domain [a,∞) and a range [b,∞) where a > 0 and b > 0?

Answer 1

Can't you just restrict the domain of a function defined over the real line

Answer 2

Take $f(x)=x$ and restrict the domain to [a,\infty) then its range will be [b,\infty)