Step-by-step explanation:
function is a binary relation between two sets that associates to each element of the first set exactly one element of the second set. for ex. if x include 1,2,3 and y include 0,9.8 we aaythere is a relation between x and y that make 1 from x equal with 0 from 7 or 3 from x equals with 8 from 6.
