Whats the answer I DONT het how to do this At all

Given that the radius r of a circle is written as a function of the area A with the following equation:
[tex]r=\sqrt[]{\frac{A}{\pi}}[/tex]The domain of the above function is the area A of the circle.
This is because, in this context, the area is an independent and unique variable.
A is the input value.