Is the set of even integers a group under addition what abou
Is the set of even integers a group under addition?
what about the set of odd integers? Why or why not?
Solution
Yes, because
The set of even integers are {- - - - ,-6,-4,-2, 0,2,4,6, - - - - -}
1) sum of any two even integers is again an even integer
so even integers are closure under addition
2) If a,b,c are any 3 even integers then a+(b+c)=(a+b)+c
so even integers satisfies associative property under addition
3) \'0\' is additive identify in set of even integers under addition
4) for every even integer 2n having inverse even integer \'-2n\' such that 2n+(-2n)=0
therefore set of integers are a group under addition
xx
but set of odd integers are not a group under addition
because sum of any two odd integers is not odd integer
since not having closure it is not a group
there is no exists additive identity also
