The value of the Euler Ï function ( Ï is the Greek letter phi) at the positive integer n is defined to be the number of positive integers less than or equal to n that are relatively prime to n. For example fon n = 14, we have {1,3,5,9,11,13} are the positive integers less than or equal to 14 which are relatively prime to 14. Thus Ï(14) = 6.
Find the following:Ï(9) =Ï(15) =Ï(75) =