maths 12th cbse

 QUESTION1:

 Let R = {(1,3), (4,2), (2,4) (2,3), (3,1)} be a relation on the set A = {1,2,3,4}. The relation R is

ANS:Not symmetric

QUESTION2:

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

ANS:(6,8)€R

QUESTION3:

The function f:N to N, given by f(x)= 2x is

ANS:One-one and onto                                                                      

QUESTION4:

Let f:R toR defined asf(x) = 3-4x, then f is

ANS:One-one and onto

QUESTION5:

Which of the following functions from Z into Z is a bijection ?

ANS: f(x)=x+2

QUESTION6:

Let T be the set of all triangles in the Euclidean plane,and let a relation R on T be defined as Rb if a is congruent to b ¥a,b € T .Then R is

ANS:Equivalence

QUESTION7:

Consider the non empty set consisting of children in a family and a relation R defined as R from a to b if a is a brother of b then R is

ANS:Transitive but not symmetric

QUESTION8:

The maximum number of equivalence relations in the set A = {1,2,3} are

ANS:5

QUESTION9:

If a relation R on the set{1,2,3} be defined by R ={(1,2)} ,then R is

ANS:Transitive

QUESTION10:

Let function f: R to R be defined f(x) = x+sin x for x € to R then f is

ANS:One - to one and onto