 # NCERT Solutions For Class 11 Maths Chapter 2 Relations and Functions

## NCERT Solutions Class 11 Maths Relations and Functions – Free PDF Download

NCERT Solutions for Class 11 Maths Chapter 2 Relations and Functions are solved in detail in the PDF given below. All the solutions to the problems in the exercises are created in such a way, that it enables the students to prepare for the exam and ace it. The NCERT Solutions are prepared by the most experienced teachers in the education space making the explanation of each solution simple, understandable and are according to the latest CBSE Syllabus 2022-23. This solution helps Class 11 students to master the concept of Relations and Functions.

The solutions provide a good understanding of the fundamental concepts before they start solving the equations. By regular practice, students will know the difference between relations and functions which is included under the syllabus and become well versed in the concepts related to it. Numerous examples are present in the textbook before the exercise questions to help them understand the methodologies to be followed while solving the problems. Referring to the NCERT Solutions PDF, students can get a glimpse of the important concepts before facing their final exams.

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Exercise 2.1 Page No: 33

1. If , find the values of x and y.

Solution:

Given, As the ordered pairs are equal, the corresponding elements should also be equal.

Thus,

x/3 + 1 = 5/3 and y – 2/3 = 1/3

Solving, we get

x + 3 = 5 and 3y – 2 = 1 [Taking L.C.M and adding]

x = 2 and 3y = 3

Therefore,

x = 2 and y = 1

2. If the set A has 3 elements and the set B = {3, 4, 5}, then find the number of elements in (A × B)?

Solution:

Given, set A has 3 elements and the elements of set B are {3, 4, and 5}.

So, the number of elements in set B = 3

Then, the number of elements in (A × B) = (Number of elements in A) × (Number of elements in B)

= 3 × 3 = 9

Therefore, the number of elements in (A × B) will be 9.

3. If G = {7, 8} and H = {5, 4, 2}, find G × H and H × G.

Solution:

Given, G = {7, 8} and H = {5, 4, 2}

We know that,

The Cartesian product of two non-empty sets P and Q is given as

P × Q = {(pq): p ∈ P, q ∈ Q}

So,

G × H = {(7, 5), (7, 4), (7, 2), (8, 5), (8, 4), (8, 2)}

H × G = {(5, 7), (5, 8), (4, 7), (4, 8), (2, 7), (2, 8)}

4. State whether each of the following statements are true or false. If the statement is false, rewrite the given statement correctly.

(i) If P = {mn} and Q = {nm}, then P × Q = {(mn), (nm)}.

(ii) If A and B are non-empty sets, then A × B is a non-empty set of ordered pairs (xy) such that x ∈ A and y ∈ B.

(iii) If A = {1, 2}, B = {3, 4}, then A × (B ∩ Φ) = Φ.

Solution:

(i) The statement is False. The correct statement is:

If P = {mn} and Q = {nm}, then

P × Q = {(mm), (mn), (n, m), (nn)}

(ii) True

(iii) True

5. If A = {–1, 1}, find A × A × A.

Solution:

The A × A × A for a non-empty set A is given by

A × A × A = {(abc): ab∈ A}

Here, It is given A = {–1, 1}

So,

A × A × A = {(–1, –1, –1), (–1, –1, 1), (–1, 1, –1), (–1, 1, 1), (1, –1, –1), (1, –1, 1), (1, 1, –1), (1, 1, 1)}

6. If A × B = {(ax), (ay), (bx), (by)}. Find A and B.

Solution:

Given,

A × B = {(ax), (a, y), (bx), (by)}

We know that the Cartesian product of two non-empty sets P and Q is given by:

P × Q = {(pq): p ∈ P, q ∈ Q}

Hence, A is the set of all first elements and B is the set of all second elements.

Therefore, A = {ab} and B = {xy}

7. Let A = {1, 2}, B = {1, 2, 3, 4}, C = {5, 6} and D = {5, 6, 7, 8}. Verify that

(i) A × (B ∩ C) = (A × B) ∩ (A × C)

(ii) A × C is a subset of B × D

Solution:

Given,

A = {1, 2}, B = {1, 2, 3, 4}, C = {5, 6} and D = {5, 6, 7, 8}

(i) To verify: A × (B ∩ C) = (A × B) ∩ (A × C)

Now, B ∩ C = {1, 2, 3, 4} ∩ {5, 6} = Φ

Thus,

L.H.S. = A × (B ∩ C) = A × Φ = Φ

Next,

A × B = {(1, 1), (1, 2), (1, 3), (1, 4), (2, 1), (2, 2), (2, 3), (2, 4)}

A × C = {(1, 5), (1, 6), (2, 5), (2, 6)}

Thus,

R.H.S. = (A × B) ∩ (A × C) = Φ

Therefore, L.H.S. = R.H.S

– Hence verified

(ii) To verify: A × C is a subset of B × D

First,

A × C = {(1, 5), (1, 6), (2, 5), (2, 6)}

And,

B × D = {(1, 5), (1, 6), (1, 7), (1, 8), (2, 5), (2, 6), (2, 7), (2, 8), (3, 5), (3, 6), (3, 7), (3, 8), (4, 5), (4, 6), (4, 7), (4, 8)}

Now, it’s clearly seen that all the elements of set A × C are the elements of set B × D.

Thus, A × C is a subset of B × D.

– Hence verified

8. Let A = {1, 2} and B = {3, 4}. Write A × B. How many subsets will A × B have? List them.

Solution:

Given,

A = {1, 2} and B = {3, 4}

So,

A × B = {(1, 3), (1, 4), (2, 3), (2, 4)}

Number of elements in A × B is n(A × B) = 4

We know that,

If C is a set with n(C) = m, then n[P(C)] = 2m.

Thus, the set A × B has 24 = 16 subsets.

And, these subsets are as below:

Φ, {(1, 3)}, {(1, 4)}, {(2, 3)}, {(2, 4)}, {(1, 3), (1, 4)}, {(1, 3), (2, 3)}, {(1, 3), (2, 4)}, {(1, 4), (2, 3)}, {(1, 4), (2, 4)}, {(2, 3), (2, 4)}, {(1, 3), (1, 4), (2, 3)}, {(1, 3), (1, 4), (2, 4)}, {(1, 3), (2, 3), (2, 4)}, {(1, 4), (2, 3), (2, 4)}, {(1, 3), (1, 4), (2, 3), (2, 4)}

9. Let A and B be two sets such that n(A) = 3 and n (B) = 2. If (x, 1), (y, 2), (z, 1) are in A × B, find A and B, where xy and z are distinct elements.

Solution:

Given,

n(A) = 3 and n(B) = 2; and (x, 1), (y, 2), (z, 1) are in A × B.

We know that,

A = Set of first elements of the ordered pair elements of A × B

B = Set of second elements of the ordered pair elements of A × B.

So, clearly xy, and z are the elements of A; and

1 and 2 are the elements of B.

As n(A) = 3 and n(B) = 2, it is clear that set A = {xyz} and set B = {1, 2}.

10. The Cartesian product A × A has 9 elements among which are found (–1, 0) and (0, 1). Find the set A and the remaining elements of A × A.

Solution:

We know that,

If n(A) = and n(B) = q, then n(A × B) = pq.

Also, n(A × A) = n(A) × n(A)

Given,

n(A × A) = 9

So, n(A) × n(A) = 9

Thus, n(A) = 3

Also given that, the ordered pairs (–1, 0) and (0, 1) are two of the nine elements of A × A.

And, we know in A × A = {(a, a): a ∈ A}.

Thus, –1, 0, and 1 has to be the elements of A.

As n(A) = 3, clearly A = {–1, 0, 1}.

Hence, the remaining elements of set A × A are as follows:

(–1, –1), (–1, 1), (0, –1), (0, 0), (1, –1), (1, 0), and (1, 1)

Exercise 2.2 Page No: 35

1. Let A = {1, 2, 3, … , 14}. Define a relation R from A to A by R = {(xy): 3x – y = 0, where xy ∈ A}. Write down its domain, codomain and range.

Solution:

The relation R from A to A is given as:

R = {(xy): 3x – y = 0, where xy ∈ A}

= {(xy): 3x = y, where xy ∈ A}

So,

R = {(1, 3), (2, 6), (3, 9), (4, 12)}

Now,

The domain of R is the set of all first elements of the ordered pairs in the relation.

Hence, Domain of R = {1, 2, 3, 4}

The whole set A is the codomain of the relation R.

Hence, Codomain of R = A = {1, 2, 3, …, 14}

The range of R is the set of all second elements of the ordered pairs in the relation.

Hence, Range of R = {3, 6, 9, 12}

2. Define a relation R on the set N of natural numbers by R = {(xy): y = x + 5, x is a natural number less than 4; xy ∈ N}. Depict this relationship using roster form. Write down the domain and the range.

Solution:

The relation R is given by:

R = {(xy): y = x + 5, x is a natural number less than 4, xy ∈ N}

The natural numbers less than 4 are 1, 2, and 3.

So,

R = {(1, 6), (2, 7), (3, 8)}

Now,

The domain of R is the set of all first elements of the ordered pairs in the relation.

Hence, Domain of R = {1, 2, 3}

The range of R is the set of all second elements of the ordered pairs in the relation.

Hence, Range of R = {6, 7, 8}

3. A = {1, 2, 3, 5} and B = {4, 6, 9}. Define a relation R from A to B by R = {(xy): the difference between x and y is odd; x ∈ A, ∈ B}. Write R in roster form.

Solution:

Given,

A = {1, 2, 3, 5} and B = {4, 6, 9}

The relation from A to B is given as:

R = {(xy): the difference between x and y is odd; x ∈ A, ∈ B}

Thus,

R = {(1, 4), (1, 6), (2, 9), (3, 4), (3, 6), (5, 4), (5, 6)}

4. The figure shows a relationship between the sets P and Q. write this relation

(i) in set-builder form (ii) in roster form.

What is its domain and range? Solution:

From the given figure, it’s seen that

P = {5, 6, 7}, Q = {3, 4, 5}

The relation between P and Q:

Set-builder form

(i) R = {(x, y): y = x – 2; x ∈ P} or R = {(x, y): y = x – 2 for x = 5, 6, 7}

Roster form

(ii) R = {(5, 3), (6, 4), (7, 5)}

Domain of R = {5, 6, 7}

Range of R = {3, 4, 5}

5. Let A = {1, 2, 3, 4, 6}. Let R be the relation on A defined by

{(ab): ab ∈ A, b is exactly divisible by a}.

(i) Write R in roster form

(ii) Find the domain of R

(iii) Find the range of R.

Solution:

Given,

A = {1, 2, 3, 4, 6} and relation R = {(ab): ab ∈ A, b is exactly divisible by a}

Hence,

(i) R = {(1, 1), (1, 2), (1, 3), (1, 4), (1, 6), (2, 2), (2, 4), (2, 6), (3, 3), (3, 6), (4, 4), (6, 6)}

(ii) Domain of R = {1, 2, 3, 4, 6}

(iii) Range of R = {1, 2, 3, 4, 6}

6. Determine the domain and range of the relation R defined by R = {(xx + 5): x ∈ {0, 1, 2, 3, 4, 5}}.

Solution:

Given,

Relation R = {(xx + 5): x ∈ {0, 1, 2, 3, 4, 5}}

Thus,

R = {(0, 5), (1, 6), (2, 7), (3, 8), (4, 9), (5, 10)}

So,

Domain of R = {0, 1, 2, 3, 4, 5} and,

Range of R = {5, 6, 7, 8, 9, 10}

7. Write the relation R = {(xx3): is a prime number less than 10} in roster form.

Solution:

Given,

Relation R = {(xx3): is a prime number less than 10}

The prime numbers less than 10 are 2, 3, 5, and 7.

Therefore,

R = {(2, 8), (3, 27), (5, 125), (7, 343)}

8. Let A = {xy, z} and B = {1, 2}. Find the number of relations from A to B.

Solution:

Given, A = {xy, z} and B = {1, 2}.

Now,

A × B = {(x, 1), (x, 2), (y, 1), (y, 2), (z, 1), (z, 2)}

As n(A × B) = 6, the number of subsets of A × B will be 26.

Thus, the number of relations from A to B is 26.

9. Let R be the relation on Z defined by R = {(ab): ab ∈ Z, – b is an integer}. Find the domain and range of R.

Solution:

Given,

Relation R = {(ab): ab ∈ Z, – b is an integer}

We know that the difference between any two integers is always an integer.

Therefore,

Domain of R = Z and Range of R = Z

Exercise 2.3 Page No: 44

1. Which of the following relations are functions? Give reasons. If it is a function, determine its domain and range.

(i) {(2, 1), (5, 1), (8, 1), (11, 1), (14, 1), (17, 1)}

(ii) {(2, 1), (4, 2), (6, 3), (8, 4), (10, 5), (12, 6), (14, 7)}

(iii) {(1, 3), (1, 5), (2, 5)}

Solution:

(i) {(2, 1), (5, 1), (8, 1), (11, 1), (14, 1), (17, 1)}

As 2, 5, 8, 11, 14, and 17 are the elements of the domain of the given relation having their unique images, this relation can be called as a function.

Here, domain = {2, 5, 8, 11, 14, 17} and range = {1}

(ii) {(2, 1), (4, 2), (6, 3), (8, 4), (10, 5), (12, 6), (14, 7)}

As 2, 4, 6, 8, 10, 12, and 14 are the elements of the domain of the given relation having their unique images, this relation can be called as a function.

Here, domain = {2, 4, 6, 8, 10, 12, 14} and range = {1, 2, 3, 4, 5, 6, 7}

(iii) {(1, 3), (1, 5), (2, 5)}

It’s seen that the same first element i.e., 1 corresponds to two different images i.e., 3 and 5, this relation cannot be called as a function.

2. Find the domain and range of the following real function:

(i) f(x) = –|x| (ii) f(x) = √(9 – x2

Solution:

(i) Given,

f(x) = –|x|, x ∈ R

We know that, As f(x) is defined for x ∈ R, the domain of f is R.

It is also seen that the range of f(x) = –|x| is all real numbers except positive real numbers.

Therefore, the range of f is given by (–∞, 0].

(ii) f(x) = √(9 – x2)

As √(9 – x2) is defined for all real numbers that are greater than or equal to –3 and less than or equal to 3, for 9 – x2 ≥ 0.

So, the domain of f(x) is {x: –3 ≤ x ≤ 3} or [–3, 3].

Now,

For any value of x in the range [–3, 3], the value of f(x) will lie between 0 and 3.

Therefore, the range of f(x) is {x: 0 ≤ x ≤ 3} or [0, 3].

3. A function f is defined by f(x) = 2x – 5. Write down the values of

(i) f(0), (ii) f(7), (iii) f(–3)

Solution:

Given,

Function, f(x) = 2x – 5.

Therefore,

(i) f(0) = 2 × 0 – 5 = 0 – 5 = –5

(ii) f(7) = 2 × 7 – 5 = 14 – 5 = 9

(iii) f(–3) = 2 × (–3) – 5 = – 6 – 5 = –11

4. The function ‘t’ which maps temperature in degree Celsius into temperature in degree Fahrenheit is defined by .

Find (i) t (0) (ii) t (28) (iii) t (–10) (iv) The value of C, when t(C) = 212

Solution: 5. Find the range of each of the following functions.

(i) f(x) = 2 – 3xx ∈ R, x > 0.

(ii) f(x) = x2 + 2, x is a real number.

(iii) f(x) = xx is a real number.

Solution:

(i) Given,

f(x) = 2 – 3xx ∈ R, x > 0. We have,

x > 0

So,

3x > 0

-3x < 0 [Multiplying by -1 both the sides, the inequality sign changes]

2 – 3x < 2

Therefore, the value of 2 – 3x is less than 2.

Hence, Range = (–∞, 2)

(ii) Given,

f(x) = x2 + 2, x is a real number We know that,

x2 ≥ 0

So,

x2 + 2 ≥ 2 [Adding 2 both the sides]

Therefore, the value of x2 + 2 is always greater or equal to 2 for x is a real number.

Hence, Range = [2, ∞)

(iii) Given,

f(x) = x, x is a real number

Clearly, the range of f is the set of all real numbers.

Thus,

Range of f = R

Miscellaneous Exercise Page No: 46

1. The relation f is defined by The relation g is defined by Show that f is a function and g is not a function.

Solution:

The given relation f is defined as: It is seen that, for 0 ≤ x < 3,

f(x) = x2 and for 3 < x ≤ 10,

f(x) = 3x

Also, at x = 3

f(x) = 32 = 9 or f(x) = 3 × 3 = 9

i.e., at x = 3, f(x) = 9 [Single image]

Hence, for 0 ≤ x ≤ 10, the images of f(x) are unique.

Therefore, the given relation is a function.

Now,

In the given relation g is defined as It is seen that, for x = 2

g(x) = 22 = 4 and g(x) = 3 × 2 = 6

Thus, element 2 of the domain of the relation g corresponds to two different images i.e., 4 and 6.

Therefore, this relation is not a function.

2. If f(x) = x2, find Solution:

Given,

f(x) = x2

Hence, 3. Find the domain of the function Solution:

Given function, . It clearly seen that, the function f is defined for all real numbers except at x = 6 and x = 2 as the denominator becomes zero otherwise.

Therefore, the domain of f is R – {2, 6}.

4. Find the domain and the range of the real function f defined by f(x) = √(x – 1).

Solution:

Given real function,

f(x) = √(x – 1)

Clearly, √(x – 1) is defined for (x – 1) ≥ 0.

So, the function f(x) = √(x – 1) is defined for x ≥ 1.

Thus, the domain of f is the set of all real numbers greater than or equal to 1.

Domain of f = [1, ∞).

Now,

As x ≥ 1 ⇒ (x – 1) ≥ 0 ⇒ √(x – 1) ≥ 0

Thus, the range of f is the set of all real numbers greater than or equal to 0.

Range of f = [0, ∞).

5. Find the domain and the range of the real function f defined by f (x) = |x – 1|.

Solution:

Given real function,

f (x) = |x – 1|

Clearly, the function |x – 1| is defined for all real numbers.

Hence,

Domain of f = R

Also, for x ∈ R, |x – 1| assumes all real numbers.

Therefore, the range of f is the set of all non-negative real numbers.

6. Let be a function from R into R. Determine the range of f.

Solution:

Given function, Substituting values and determining the images, we have The range of f is the set of all second elements. It can be observed that all these elements are greater than or equal to 0 but less than 1.

[As the denominator is greater than the numerator.]

Or,

We know that, for x ∈ R,

x2 ≥ 0

Then,

x2 + 1 ≥ x2

1 ≥ x2 / (x2 + 1)

Therefore, the range of f = [0, 1)

7. Let fg: R → R be defined, respectively by f(x) = + 1, g(x) = 2x – 3. Find f + gf – g and f/g.

Solution:

Given, the functions fg: R → R is defined as

f(x) = + 1, g(x) = 2x – 3

Now,

(f + g) (x) = f(x) + g(x) = (x + 1) + (2x – 3) = 3x – 2

Thus, (f + g) (x) = 3x – 2

(f – g) (x) = f(x) – g(x) = (x + 1) – (2x – 3) = x + 1 – 2x + 3 = – x + 4

Thus, (f – g) (x) = –x + 4

f/g(x) = f(x)/g(x), g(x) ≠ 0, x ∈ R

f/g(x) = + 1/ 2x – 3, 2x – 3 ≠ 0

Thus, f/g(x) = + 1/ 2x – 3, x ≠ 3/2

8. Let = {(1, 1), (2, 3), (0, –1), (–1, –3)} be a function from Z to Z defined by f(x) = ax + b, for some integers ab. Determine ab.

Solution:

Given, = {(1, 1), (2, 3), (0, –1), (–1, –3)}

And the function defined as, f(x) = ax + b

For (1, 1) ∈ f

We have, f(1) = 1

So, a × 1 + b = 1

a + b = 1 …. (i)

And for (0, –1) ∈ f

We have f(0) = –1

a × 0 + b = –1

b = –1

On substituting b = –1 in (i), we get

a + (–1) = 1 ⇒ a = 1 + 1 = 2.

Therefore, the values of a and b are 2 and –1, respectively.

9. Let R be a relation from N to N defined by R = {(ab): ab ∈ N and a = b2}. Are the following true?

(i) (aa) ∈ R, for all a ∈ N
(ii) (ab) ∈ R, implies (ba) ∈ R

(iii) (ab) ∈ R, (bc) ∈ R implies (ac) ∈ R.

Solution:

Given relation R = {(ab): ab ∈ N and a = b2}

(i) It can be seen that 2 ∈ N; however, 2 ≠ 22 = 4.

Thus, the statement “(aa) ∈ R, for all a ∈ N” is not true.

(ii) Its clearly seen that (9, 3) ∈ N because 9, 3 ∈ N and 9 = 32.

Now, 3 ≠ 92 = 81; therefore, (3, 9) ∉ N

Thus, the statement “(ab) ∈ R, implies (ba) ∈ R” is not true.

(iii) Its clearly seen that (16, 4) ∈ R, (4, 2) ∈ R because 16, 4, 2 ∈ N and 16 = 42 and 4 = 22.

Now, 16 ≠ 22 = 4; therefore, (16, 2) ∉ N

Thus, the statement “(ab) ∈ R, (bc) ∈ R implies (ac) ∈ R” is not true.

10. Let A = {1, 2, 3, 4}, B = {1, 5, 9, 11, 15, 16} and = {(1, 5), (2, 9), (3, 1), (4, 5), (2, 11)}. Are the following true?

(i) f is a relation from A to B (ii) f is a function from A to B.

Solution:

Given,

A = {1, 2, 3, 4} and B = {1, 5, 9, 11, 15, 16}

So,

A × B = {(1, 1), (1, 5), (1, 9), (1, 11), (1, 15), (1, 16), (2, 1), (2, 5), (2, 9), (2, 11), (2, 15), (2, 16), (3, 1), (3, 5), (3, 9), (3, 11), (3, 15), (3, 16), (4, 1), (4, 5), (4, 9), (4, 11), (4, 15), (4, 16)}

Also given that,

= {(1, 5), (2, 9), (3, 1), (4, 5), (2, 11)}

(i) A relation from a non-empty set A to a non-empty set B is a subset of the Cartesian product A × B.

It’s clearly seen that f is a subset of A × B.

Therefore, f is a relation from A to B.

(ii) As the same first element i.e., 2 corresponds to two different images (9 and 11), relation is not a function.

11. Let f be the subset of Z × Z defined by = {(aba + b): ab ∈ Z}. Is f a function from Z to Z: justify your answer.

Solution:

Given relation f is defined as

= {(aba + b): ab ∈ Z}

We know that a relation f from a set A to a set B is said to be a function if every element of set A has unique images in set B.

As 2, 6, –2, –6 ∈ Z, (2 × 6, 2 + 6), (–2 × –6, –2 + (–6)) ∈ f

i.e., (12, 8), (12, –8) ∈ f

It’s clearly seen that, the same first element, 12 corresponds to two different images (8 and –8).

Therefore, the relation f is not a function.

12. Let A = {9, 10, 11, 12, 13} and let f: A → N be defined by f(n) = the highest prime factor of n. Find the range of f.

Solution:

Given,

A = {9, 10, 11, 12, 13}

Now, f: A → N is defined as

f(n) = The highest prime factor of n

So,

Prime factor of 9 = 3

Prime factors of 10 = 2, 5

Prime factor of 11 = 11

Prime factors of 12 = 2, 3

Prime factor of 13 = 13

Thus, it can be expressed as

f(9) = The highest prime factor of 9 = 3

f(10) = The highest prime factor of 10 = 5

f(11) = The highest prime factor of 11 = 11

f(12) = The highest prime factor of 12 = 3

f(13) = The highest prime factor of 13 = 13

The range of f is the set of all f(n), where n ∈ A.

Therefore,

Range of f = {3, 5, 11, 13}

 Also Access NCERT Exemplar for Class 11 Maths Chapter 2 CBSE Notes for Class 11 Maths Chapter 2

### NCERT Solutions for Class 11 Maths Chapter 2- Relations and Functions

The following ideas of Chapter 2 Relations & Functions for Class 11 are given elaborately.

2.1 Introduction

This section introduces the concepts covered in the chapter Relations and Functions.

The combination of the register number of the student and his corresponding height is a relationship, which can be written as a set of ordered-pair numbers. Ordered-pair numbers are expressed as (x, y). The set of all elements of x is called the domain of the relation and the set of all elements of y is called the range of the relation.

2.2 Cartesian Product of Sets

This section defines the cartesian product and ordered pairs by giving a real-life model, its representation and some worked examples.

Lindt chocolates come in five shapes, three flavours and in six colours.

C :={circle, triangle, rectangle, rhombus, square}

N :={orange, vanilla, peach}

S :={red, blue, pink, white, yellow, purple}

C:={circle, triangle, rectangle, rhombus, square}, N:={orange, vanilla, peach}, S:={red, blue, pink, white, yellow, purple}

be the five shapes, three flavours and six colours, respectively. Then the set of all chocolates to be manufactured in the triple cartesian product C×N×S and consists of 5⋅3⋅6=90 elements. As a manager, to sell this set of chocolates would have to make room for 90 heaps.

2.3 Relations

This section explains the mapping of set A to set B with a few solved problems. Definitions of domain and codomain are also introduced.

The idea of mapping a particular phone number to the respective person to whom the number belongs to. That’s a relation — from phone number to person.

2.4 Functions

This section covers functions, visualisation of functions, how is a relation said to be a function with a few examples. Meaning of image and preimage.

The height of a person can be determined by the length of his femur bone. Hence, it is an example of a function.

2.4.1 Some functions and their graphs

This section talks about different types of functions and their graphical representations. Some of the types of functions are listed below.

• Identity function
• Constant function
• Polynomial function
• Rational functions
• The Modulus function
• Signum function
• Greatest integer function

2.4.2 Algebra of real functions

This section includes the algebraic operations on functions.

• Addition of two real functions
• Subtraction of a real function from another
• Multiplication by a scalar
• Multiplication of two real functions
• The quotient of two real functions

Exercise 2.1 Solutions 10 Questions

Exercise 2.2 Solutions 9 Questions

Exercise 2.3 Solutions 5 Questions

Miscellaneous Exercise On Chapter 2 Solutions 12 Questions

#### Key Features of NCERT Solutions for Class 11 Maths Chapter 2- Relations and Functions

• The two elements which are grouped in particular order are termed as ordered pair.
• Cartesian product A × B of two sets A and B is given by A × B = {(a, b): a ∈ A, b ∈ B}
• Relation R from a set A to a set B is a subset of the cartesian product A × B obtained by explaining the relationship between the first element x and the second element y of the ordered pairs in A × B.
• The image of an element x under a relation R is given by y, where (x, y) ∈ R.
• The domain of R is the set of all first elements of the ordered pairs in a relation R.
• The range of a relation R is the set of all second elements of the ordered pairs in a relation R.
• Function A from a set A to a set B is a specific type of relation for which every element x of set A has one and only one image y in set B. We write f: A→B, where f(x) = y.
• The range of the function is the set of images.
• A real function has the set of real numbers or one of its subsets both as to its domain and as its range.

Basic concepts are covered in the NCERT Solutions for Class 11 Maths modules aid students to move ahead in their area of work. The latest update of the CBSE Syllabus 2022-23 ensures that the content covered is apt for the students to move ahead in their respective streams in the future. A student needs to understand the concept of Relations and Functions as it covers the main chunk in the question paper. Before solving real-world applications and problems, the concept has to be learned thoroughly.

## Frequently Asked Questions on NCERT Solutions for Class 11 Maths Chapter 2

### How to find which relation is a function in Chapter 2 of NCERT Solutions for Class 11 Maths?

According to the definition, a function can relate every element which is present in a domain to only one element which is found in the range. It means that any vertical line drawn by a student on a graph can pass through the x-axis only once. A relation from a function can be found out by using vertical line tests or with the help of different formulas.

### Explain the basic steps for the Cartesian product of sets in NCERT Solutions for Class 11 Maths Chapter 2 Relations and Functions.

In order to understand the basic steps for solving a question regarding Cartesian product of sets, students must comprehend the first exercise of this chapter thoroughly. Students are provided with solved examples before each exercise wise problems in order help them understand the method of solving problems in a shorter duration. By solving the problems from the NCERT textbook, students will improve their conceptual understanding which is necessary in order to perform well in the exams.

### What is the meaning of relations in Chapter 2 of NCERT Solutions for Class 11 Maths?

Relations are nothing but the collection of ordered pairs which has one object from every set. A function can also be considered as a relation but the conceptual idea of both of them are completely different. The NCERT Solutions for Class 11 Maths Chapter 2 provides the students with proper definition and analysis of relations as per the CBSE Syllabus 2022-23. Several examples present in the solutions will help students in solving the problems related to relations without any difficulty.