Basics of Relations

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Basics of Relations: Overview

This topic covers concepts, such as Definition of Relations on a Set, Domain, Co-domain and Range of a Relation, Representation of a Relation, Representation of a Relation by Set-builder Method, Representation of a Relation by Roster Method, etc.

Important Questions on Basics of Relations

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If A is non-empty, then any subset of A×A is called 

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A relation on set A is a subset of 

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If A is finite set containing m elements, then the number of relations from A to A is equal to 

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If A and B are finite sets containing m and n elements respectively, then the number of relations from A to B is equal to 

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If A=1,-1B=2,5, then the number of relationships from A to B is

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Let A=2,3,4 and B=8,9,12. Then the number of elements in the relation  R=a1,b1,a2,b2A×B,A×B:a1 divides b2 and a2 divides b1 is

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Assertion A: Domain and range of a relation R=x,y:x-3y=0 defined on the set A=1,2,3 are respectively 1,2,3 and 2,4,6.

Reason R: Domain and Range of a relation R are respectively the sets a:aA and a,bR and b:bA and a,bR

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Let nA=m and nB=n, then the total number of non-empty relations that can be defined from A to B is:

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If R is a relation on finite set A having n elements, then the number of relations on A is

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If nA=2 and nB=3, then write the total number of non empty relations that can be defined from A to B

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Let A=1,2,3,4,5 and let B=1,2,3,4. If the relation R:AB is given by a,bR if and only if a+b is even, then nR is equal to

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Let A=x:x2<26 and x is a prime number and B=y:y1 and y is a whole number,then the number of relations  from B to A will be

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If a,bR such that a2+1=b where relation R is subset of A×B, then the number of elements in range of relation R where A=-1,0,1,2 and B=1,2,3.

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Let A and B be two smallest sets such that A1=1,2,3,4 and B5=4,5,6,7,8. If P=A-B and Q=B-A, then the number of relations from P to Q is

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If (a,b)R such that a2+1=b where relation R is subset of A×B, then number of elements in range of relation R (whereA={-1,0,1,2} and B={1,2,3}.

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Set A has 5 elements, the set B has 4 elements, the number of relations from a set A to a set B is 

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A type of representation that represents a relation is

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For the function h(x)=101+x the domain of real values of x where 0x9, the range is

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The range of the function f(x)=log10(1+x) for the domain of real values of x when 0x9 is

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The function f(x)=2x is