English

Defines a relation on N: xy is square of an integer, x, y ∈ N Determine the above relation is reflexive, symmetric and transitive. - Mathematics

Advertisements
Advertisements

Question

Defines a relation on N:

xy is square of an integer, x, y ∈ N

Determine the above relation is reflexive, symmetric and transitive.

Sum
Advertisements

Solution

On natural numbers N:

xRy if xy is a perfect square

Check Each Property:

Reflexive: 
x ⋅ x = x2 is always a perfect square.
So, the relation is reflexive.

Symmetric:

If xy is a perfect square, then yx is the same.
So, the relation is symmetric.

Transitive (Not always):

Even if xy and yz are perfect squares,

xz may not be a perfect square.

(Example: x = 1, y = 4, z = 2:
xy = 4, yz = 8 → but yz is not a perfect square)

The relation is reflexive and symmetric, but not transitive.

shaalaa.com
  Is there an error in this question or solution?
Chapter 1: Relations - Exercise 1.1 [Page 11]

APPEARS IN

RD Sharma Mathematics [English] Class 12
Chapter 1 Relations
Exercise 1.1 | Q 18.3 | Page 11

RELATED QUESTIONS

Determine whether the following relation is reflexive, symmetric and transitive:

Relation R in the set A = {1, 2, 3, ..., 13, 14} defined as R = {(x, y) : 3x − y = 0}.


Show that the relation R in R defined as R = {(a, b) : a ≤ b}, is reflexive and transitive but not symmetric.


Let A = {1, 2, 3}. Then number of relations containing (1, 2) and (1, 3) which are reflexive and symmetric but not transitive is

(A) 1 (B) 2 (C) 3 (D) 4


The binary operation *: R x R → R is defined as a *b = 2a + b Find (2 * 3)*4


Test whether the following relation R3 is (i) reflexive (ii) symmetric and (iii) transitive:

R3 on R is defined by (a, b) ∈ R3 `⇔` a2 – 4ab + 3b2 = 0.


If = {1, 2, 3, 4} define relations on A which have properties of being reflexive, symmetric and transitive ?


An integer m is said to be related to another integer n if m is a multiple of n. Check if the relation is symmetric, reflexive and transitive.


Give an example of a relation which is reflexive and transitive but not symmetric?


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


If R = {(x, y) : x2 + y2 ≤ 4; x, y ∈ Z} is a relation on Z, write the domain of R.


Define an equivalence relation ?


Let the relation R be defined on N by aRb iff 2a + 3b = 30. Then write R as a set of ordered pairs


Let R be a relation on the set N given by
R = {(a, b) : a = b − 2, b > 6}. Then,


Let A = {1, 2, 3}. Then, the number of relations containing (1, 2) and (1, 3) which are reflexive and symmetric but not transitive is ______.


Let R be a relation on N defined by x + 2y = 8. The domain of R is _______________ .


Let A = {1, 2, 3} and B = {(1, 2), (2, 3), (1, 3)} be a relation on A. Then, R is ________________ .


Mark the correct alternative in the following question:

Let A = {1, 2, 3} and consider the relation R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3), (1, 3)}. Then, R is _______________ .


Mark the correct alternative in the following question:

Let L denote the set of all straight lines in a plane. Let a relation R be defined by lRm if l is perpendicular to m for all l, m  L. Then, R is ______________ .


If `f(x) = (4x + 3)/(6x - 4), x ≠ 2/3`, show that fof (x) = x for all `x ≠ 2/3`. Also, find the inverse of f.


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


If A = {a, b, c}, B = (x , y} find B × A.


Write the relation in the Roster form and hence find its domain and range:

R2 = `{("a", 1/"a")  "/"  0 < "a" ≤ 5, "a" ∈ "N"}`


R = {(a, b) / b = a + 1, a ∈ Z, 0 < a < 5}. Find the Range of R.


For real numbers x and y, define xRy if and only if x – y + `sqrt(2)` is an irrational number. Then the relation R is ______.


Consider the set A = {1, 2, 3} and R be the smallest equivalence relation on A, then R = ______


Given A = {2, 3, 4}, B = {2, 5, 6, 7}. Construct an example of the following:
a mapping from B to A


Let the relation R be defined in N by aRb if 2a + 3b = 30. Then R = ______.


Let A = { 2, 3, 6 } Which of the following relations on A are reflexive?


Let R be the relation on N defined as by x + 2 y = 8 The domain of R is ____________.


Let A = {1, 2, 3}. Which of the following is not an equivalence relation on A?


A relation R on a non – empty set A is an equivalence relation if it is ____________.


Let R be the relation “is congruent to” on the set of all triangles in a plane is ____________.


Given set A = {1, 2, 3} and a relation R = {(1, 2), (2, 1)}, the relation R will be ____________.


A relation S in the set of real numbers is defined as `"xSy" => "x" - "y" + sqrt3`  is an irrational number, then relation S is ____________.


A general election of Lok Sabha is a gigantic exercise. About 911 million people were eligible to vote and voter turnout was about 67%, the highest ever


Let I be the set of all citizens of India who were eligible to exercise their voting right in the general election held in 2019. A relation ‘R’ is defined on I as follows:

R = {(V1, V2) ∶ V1, V2 ∈ I and both use their voting right in the general election - 2019}

  • Mr. Shyam exercised his voting right in General Election-2019, then Mr. Shyam is related to which of the following?

Sherlin and Danju are playing Ludo at home during Covid-19. While rolling the dice, Sherlin’s sister Raji observed and noted the possible outcomes of the throw every time belongs to set {1,2,3,4,5,6}. Let A be the set of players while B be the set of all possible outcomes.

A = {S, D}, B = {1,2,3,4,5,6}

  • Let R ∶ B → B be defined by R = {(x, y): y is divisible by x} is ____________.

Let R = {(x, y) : x, y ∈ N and x2 – 4xy + 3y2 = 0}, where N is the set of all natural numbers. Then the relation R is ______.


lf A = {x ∈ z+ : x < 10 and x is a multiple of 3 or 4}, where z+ is the set of positive integers, then the total number of symmetric relations on A is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×