domain : (1,2,3........)
range: (510, 520, 530........)
domain: its like input of the function. like in this function of k(x)
x is miles and miles can't be negative so negative number can't be input of this function. just ask what are all the possible value that x can take
Range is output of function.
like: k(1)= 510 and so on
what comes out (the Range) depends on what we put in(the Domain)
Range should have single value.
