What is the domian in math?

Answer 1

In an equation like C=2PiR, the circumference (C) of a circle in terms of the radius (R), we call the values of R to be in the Domain and the values of C are then calculated and we say those results are in the Range.

So the Domain is any quantity from zero to the width of the universe if you want to be practical. I suppose that someone might like to calculate the circumference of two adjacent universes, so their Domain for R would be twice as big. Notice that the Domain contains no negative numbers. No practical circle has a negative radius.