Consider S={0,1,2} is the set of residue classes modulo 3 under addition then inverse of 2 is???

1 Answer
Jun 28, 2018

The inverse of 2 under addition modulo 3 is 1.

Explanation:

The inverse #a^-1#of an element #a# is defined such that #a+a^-1=e# where #e# is the identity element and #+# is the group operator. Since #2+1-=0 (mod3)# and #0# is the identity element in #ZZ"/"3ZZ#, the inverse of 2 is 1 in #ZZ"/"3ZZ#.