Here, we want to get the domain and range of the function
Firstly, we have to understand the concept on which we are dealing. Radius and circumference are concepts in which are measurements. As we know, we cannot have a negative value for measurement. For example, the weight of a baby cannot be -3kg. In likewise manner, we cannot have the measurements as equal to zero.
A circle of 0 cm radius does not exist
So, what these mean is that the radius and the circumference are values that cannot be equal to zero or less than zero.
The range refers to the values the y-axis can take while the domain are the values we can have on the x-axis
So, simply put;
a) Domain;
[tex]0\text{ }<\text{ x }<\text{ +}\infty[/tex]
b) Range;
[tex]0Where the term positive infinity is the greatest positive number. Also, we must note that the radius or circumference value cannot be equal to positive infinity (a circle that has an infinite radius value does not exist)
