NCERT Exemplar Solutions
Class 11 - Mathematics - Chapter 2: RELATIONS AND FUNCTIONS
Objective Type Questions

Choose the correct answers in Exercises from 24 to 35 (M.C.Q.)

Question.  24

Let \( n(A)=m \) and \( n(B)=n \). Then the total number of non-empty relations that can be defined from A to B is

(a)

\( m^n \)

(b)

\( n^m - 1 \)

(c)

\( mn - 1 \)

(d)

\( 2^{mn} - 1 \)

Question.  25

If \( [x]^2 - 5[x] + 6 = 0 \), where \([.]\) denotes the greatest integer function, then

(a)

\( x \in [3,4] \)

(b)

\( x \in (2,3] \)

(c)

\( x \in [2,3] \)

(d)

\( x \in [2,4] \)

Question.  26

The range of \( f(x)=\dfrac{1}{1-2\cos x} \) is

(a)

\( \left[\dfrac{1}{3},1\right] \)

(b)

\( [-1,\tfrac{1}{3}] \)

(c)

\( (-\infty,-1] \cup [\tfrac{1}{3},\infty) \)

(d)

\( [-\tfrac{1}{3},1] \)

Question.  27

Let \( f(x)=\sqrt{1+x^2} \). Then

(a)

\( f(xy)=f(x)f(y) \)

(b)

\( f(xy)\ge f(x)f(y) \)

(c)

\( f(xy)\le f(x)f(y) \)

(d)

None of these

Question.  28

The domain of \( \sqrt{a^2-x^2} \) where \( a>0 \) is

(a)

\( (-a,a) \)

(b)

\( [-a,a] \)

(c)

\( [0,a] \)

(d)

\( (-a,0] \)

Question.  29

If \( f(x)=ax+b \), where \( a,b \) are integers, \( f(-1)=-5 \) and \( f(3)=3 \), then \( a \) and \( b \) are

(a)

\( a=-3, b=-1 \)

(b)

\( a=2, b=-3 \)

(c)

\( a=0, b=2 \)

(d)

\( a=2, b=3 \)

Question.  30

The domain of the function defined by \( f(x)=\sqrt{4-x}+\dfrac{1}{\sqrt{x^2-1}} \) is

(a)

\( (-\infty,-1) \cup (1,4] \)

(b)

\( (-\infty,-1] \cup (1,4] \)

(c)

\( (-\infty,-1) \cup [1,4] \)

(d)

None of these

Question.  31

The domain and range of the real function \( f(x)=\dfrac{4-x}{x-4} \) is

(a)

Domain = \( \mathbb{R} \), Range = \{ -1, 1 \}

(b)

Domain = \( \mathbb{R}-\{1\} \), Range = \( \mathbb{R} \)

(c)

Domain = \( \mathbb{R}-\{4\} \), Range = \{ -1 \}

(d)

Domain = \( \mathbb{R}-\{4\} \), Range = \{ -1,1 \}

Question.  32

The domain and range of the function \( f(x)=\sqrt{x-1} \) is

(a)

Domain = \( (1,\infty) \), Range = \( (0,\infty) \)

(b)

Domain = \( [1,\infty) \), Range = \( 0,\infty) \)

(c)

Domain = \( [1,\infty) \), Range = \( [0,\infty) \)

(d)

Domain = \( [1,\infty) \), Range = \( [0,\infty) \)

Question.  33

The domain of the function \( f(x)=\dfrac{x^2+2x+1}{x^2-x-6} \) is

(a)

\( \mathbb{R}-\{3,-2\} \)

(b)

\( \mathbb{R}-\{-3,2\} \)

(c)

\( \mathbb{R}-[3,-2] \)

(d)

\( \mathbb{R}-(3,-2) \)

Question.  34

The domain and range of the function \( f(x)=2-|x-5| \) is

(a)

Domain = \( \mathbb{R}^+ \), Range = \((-\infty,1] \)

(b)

Domain = \( \mathbb{R} \), Range = \((-\infty,2] \)

(c)

Domain = \( \mathbb{R} \), Range = \((-\infty,2) \)

(d)

Domain = \( \mathbb{R}^+ \), Range = \((-\infty,2] \)

Question.  35

The domain for which the functions \( f(x)=3x^2-1 \) and \( g(x)=3+x \) are equal is

(a)

\( \{-1,\dfrac{4}{3}\} \)

(b)

\( \left\{-1,\dfrac{4}{3}\right\} \)

(c)

\( \{-1,\dfrac{4}{3}\} \)

(d)

\( \{-1,\dfrac{4}{3}\} \)

NCERT Exemplar Solutions Class 11 – Mathematics – Chapter 2: RELATIONS AND FUNCTIONS – Objective Type Questions | Detailed Answers