

InterviewSolution
Saved Bookmarks
1. |
Statement-1: The relation R on the set `N xx N` defined by (a, b) R (c, d) `iff` a+d = b+c for all a, b, c, d `in` N is an equivalence relation. Statement-2: The intersection of two equivalence relations on a set A is an equivalence relation. |
Answer» (i) (a,b) R (a,b) implies a + b = b + a `therefore` R is reflexive. (ii) (a, b) R (c, d) implies a + d = b + c `implies c+b=d+aimplies(c,d)R(a,b)` `therefore R` is symmetric. (iii) (a, b) R (c, d) and (c, d) R (e, f) implies a + d = b + c and c + f = d + e `impliesa+d+c+f=b+c+d+e` `impliesa+f=b+eimplies(a,b)R(e,f)` `therefore R` is transitive. Thus, R is an equivalence relation on `NxxN`. |
|