Home
Class 12
MATHS
Prove that a relation R defined on NxxN ...

Prove that a relation R defined on `NxxN` where `(a, b)R(c, d) <=> ad = bc` is an equivalence relation.

Text Solution

Verified by Experts

R defined on `N xx N` such that (a, b) R (c, d) `iff` ad = bc
Reflexivity Let (a, b) `in N xx N`
`implies a, b in N implies ab = ba`
implies (a, b) R (a, b)
`therefore` R is reflexive on, `N xx N`.
Symmetry Let (a, b), (c, d) `in N xx N`,
then (a, b) R (c, d) implies ad = bc
implies cb = da
implies (c, d) R (a, b)
`therefore` R is symmetric on `N xx N`
Transitivity Let `(a, b), (c, d), (e, f), in N xx N`.
Then, (a, b) R (c, d) implies ad = bc ... (i)
(c, d) R (e, f) implies cf = de ... (ii)
From Eqs. (i) and (ii), (ad) (cf) = (bc) (de)
implies af = be
implies (a, b) R (e, f)
`therefore` R is transitive relation on `N xx N`.
`therefore R` is equivalence relations on `N xx N`.
Doubtnut Promotions Banner Mobile Dark
|

Similar Questions

Explore conceptually related problems

R is relation in N xxN as (a,b) R (c,d) hArr ad = bc . Show that R is an equivalence relation.

Show that the relation R defined by (a,b) R (c,d) implies a + d = b +c on the set N xxN is an equivalence relation.

The relation R difined the set Z as R = {(x,y) : x - yin Z} show that R is an equivalence relation.

A = {(1,2,3,......10} The relation R defined in the set A as R = {(x,y) : y = 2x} . Show that R is not an equivalence relation.

Let f: X rarrY be a function. Define a relation R in X given by R = {(a, b): f(a) = f(b)} . Examine whether R is an equivalence relation or not.

In order that a relation R defined on a non-empty set A is an equivalence relation, it is sufficient, if R

Show that the relation R in the set Z of intergers given by R ={(a,b):2 divides a-b } is an equivalence relation.

Let N denote the set of all natural numbers and R be the relation on NxN defined by (a , b)R(c , d) a d(b+c)=b c(a+d)dot Check whether R is an equivalence relation on NxNdot

Let n be a fixed positive integer. Define a relation R on Z as follows: (a , b)R a-b is divisible by ndot Show that R is an equivalence relation on Zdot

Let R be a relation on the set A of ordered pairs of positive integers defined by (x, y) R (u, v) if and only if xv= yu. Show that R is an equivalence relation.