Consider the function [tex]f(x)=\sqrt{x}.[/tex] This function has:
- the domain [tex]x\in [0,\infty);[/tex]
- the range [tex]y\in [0,\infty).[/tex]
If the domain of unknown function is [tex][a,\infty),[/tex] then [tex]x\ge a[/tex] or [tex]x-a\ge 0.[/tex] This means that you have [tex]\sqrt{x-a}[/tex] as a part of needed function.
If the range of unknown function is [tex][b,\infty),[/tex] then [tex]y\ge b.[/tex] This means that you have to translate function b units up and then the expression of the function is
[tex]y=\sqrt{x-a}+b.[/tex]
Answer: correct choice is B.
