Relations and Functions (Class 12) · Question 2

Let f: R R be defined as f(x)= 2x2-3x+23x2+x+3. Then f is :

1. both one-one and onto
2. one-one but not onto
3. onto but not one-one
4. neither one-one nor onto

Let R= \(x, y) N N : e(x+y) 2 \. Then the minimum number of elements, required to be added in R to make it a transitive relation, is .

Let A=\1, 2, 3, 4, 5, 6\. The number of one-one functions f : A A such that f(1) 3, f(3) 4 and f(2)+f(3)=5, is .

The number of functions f : \1, 2, 3, 4\ \a, b, c\, which are not onto, is :

1. 48
2. 45
3. 51
4. 35

For the function f : [1, ) [1, ) defined by f(x)=(x-1)4+1, among the two statements : (I) The set S=\x [1, ) : f(x)=f-1(x)\ contains exactly two elements, and (II) The set S=\x [1, ) : f(x)=f-1(x+1)\ is an empty set,

1. only (I) is TRUE
2. only (II) is TRUE
3. both (I) and (II) are TRUE
4. neither (I) nor (II) is TRUE

Let for some R, f : R R be a function satisfying f(x+y)=f(x)+2y2+y+ xy for all x, y R. If f(0)=-1 and f(1)=2, then the value of n=15 ( +f(n) ) is :

1. 110
2. 140
3. 150
4. 170

If g(x) = 3x2 + 2x - 3, f(0) = -3 and 4g(f(x)) = 3x2 - 32x + 72, then f(g(2)) is equal to:

1. 72
2. - 256
3. 256
4. - 72

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Statement I is true but Statement II is false
2. Both Statement I and Statement II are false
3. Both Statement I and Statement II are true
4. Statement I is false but Statement II is true

Let R be a relation defined on the set \1, 2, 3, 4\ \1, 2, 3, 4\ by R = \((a, b), (c, d)) : 2a + 3b = 3c + 4d\. Then the number of elements in R is

1. 6
2. 15
3. 12
4. 18

Let f be a function such that 3f(x) + 2f ( m19x ) = 5x, x 0, where m = i=19 (i)2. Then f(5) - f(2) is equal to

1. 36
2. 9
3. -9
4. 18