I dont understand what the second part of the question is asking for. My book only shows examples asking for a single functions such as r_{1}(t) and not r_{2}(t).

In r_{2}(t) can I let x = anything with a value of t in it? Such as x=(2-t) and then y would be y=Sqrt(2-t) ? I tried that but it was incorrect. Im stuck on this question. Any help would be appreciated.