The radius r of a circle can be written as a function of the area a with the following equation: what is the domain of this function? explain why it makes sense in this context.

The real formula of the radius is r = √(A/pi)

 In this context, it makes sense as the radius cannot have a negative value. 

Thus, the domain of the function is [0,∞)

This means that the Area can have any positive value starting from zero.