CBSE Guess > Papers > Important Questions > Class XII > 2008 > Maths > Maths By Mrs. Geethanjali Bhatt CBSE CLASS XII Q. 1. Let A = {1,2,3,4} find the number of relations on A containing (1, 2) and (3, 2) which is reflexive transitive but not symmetric giving sufficient reasons. Q. 2. Let R be the set of real numbers on ‘R’ defined by R = {(a,b) /  ab  < 5} is not transitive . Prove the above statement by giving two examples. Q. 3.
Q. 4. Let Q be the set of all rational numbers on R be the relation on Q defined by R = { (x,y) : 1 + xy > 0} Find whether relation is equivalence. Q. 5. f : z > z f(x) = x^{2} + x. rove that the function is neither injective nor subjective. Q. 6. Let where f(x) = x2 – x+ 1.Prove that f is invertible and hence find f ^{1}. Q. 7. Let f: N > Y be a function defined by f(x) = x^{2} + 1 Show that f is one – one and replace Y by a set so that f is invertible. Also find its inverse function. Q. 8. Let f : R > R g: R > R defined by
Q. 9.Let N be the set of all natural numbers. R be the relation on N X N defined by (a,b) R (c,d) iff ad = bc Show that R is equivalence. Q. 10. Q. 11.
Q. 12. A function f over the set of real numbers is defined as Find whether the function is oneone or onto

