1st post here.
I came across this problem in a GMAT reviewer and I naturally got B, but the correct answer is listed as A.
There was a brief explanation about why the answer is A: (2-x)^(1/2), but the brief explanation confused me. I realize that x>=2, but I don't see how I can use that to get the correct answer.
I guess I need to review some basic properties of abs value, roots, and inequalities
"Every non-negative real number x has a unique non-negative square root, called the principal square root, which is denoted by , where is called radical sign."
I'm not aware of any convention where it is possible that .