Matching Items MCQs for Sub-Topics of Topic 9: Sets, Relations & Functions Content On This Page | ||
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Sets: Fundamentals and Representation | Sets: Types and Cardinality | Set Relations |
Types of Relations | Set Operations and Venn Diagrams | Algebra of Sets and Cardinality Results |
Functions: Definition, Domain, and Range | Types of Functions | Real Functions and Their Graphs |
Operations on Functions | Invertible Functions and Binary Operations |
Matching Items MCQs for Sub-Topics of Topic 9: Sets, Relations & Functions
Sets: Fundamentals and Representation
Question 1. Match the following sets described in Set-Builder form with their Roster form:
(i) $\{x : x \text{ is a prime number less than 10}\}$
(ii) $\{x : x^2 = 16, x \in \mathbb{Z}\}$
(iii) $\{x : x \text{ is a letter in the word 'INDIA'}\}$
(iv) $\{x : x \in \mathbb{N}, x \leq 3\}$
(v) $\{x : x \text{ is an odd integer between 4 and 10}\}$
(a) $\{-4, 4\}$
(b) $\{I, N, D, A\}$
(c) $\{1, 2, 3\}$
(d) $\{5, 7, 9\}$
(e) $\{2, 3, 5, 7\}$
Answer:
Question 2. Match the standard sets of numbers with their descriptions:
(i) $\mathbb{N}$
(ii) $\mathbb{Z}$
(iii) $\mathbb{Q}$
(iv) $\mathbb{R}$
(v) $\mathbb{C}$
(a) Set of rational numbers
(b) Set of complex numbers
(c) Set of integers
(d) Set of natural numbers
(e) Set of real numbers
Answer:
Question 3. Match the following related to Cartesian Products:
(i) $A = \{1\}$, $B=\{a\}$, $A \times B$ is
(ii) $A = \{1, 2\}$, $B=\{a\}$, $n(A \times B)$ is
(iii) $A = \{1, 2\}$, $A \times A$ has elements
(iv) $(x, y) = (3, 5)$ implies
(v) A relation from A to B is a subset of
(a) $x=3$ and $y=5$
(b) 4
(c) $A \times B$
(d) 2
(e) $\{(1, a)\}$
Answer:
Question 4. Match the set descriptions with the correct symbol or term:
(i) A well-defined collection of objects
(ii) Symbol for 'is an element of'
(iii) Representation listing elements
(iv) Representation using a property
(v) The elements $a$ and $b$ in $(a, b)$
(a) Roster form
(b) Ordered Pair Components
(c) Set
(d) $\in$
(e) Set-builder form
Answer:
Question 5. Match the following properties of ordered pairs:
(i) Equality condition for $(a, b) = (c, d)$
(ii) Number of elements in $A \times B$ if $n(A)=p, n(B)=q$
(iii) Example of an ordered pair
(iv) Set of all ordered pairs $(a, b)$ from A to B
(v) Order matters in
(a) $(5, \textsf{₹}100)$
(b) Cartesian Product $A \times B$
(c) $a=c$ and $b=d$
(d) Ordered Pair
(e) $pq$
Answer:
Sets: Types and Cardinality
Question 1. Match the types of sets with their definitions:
(i) Empty Set
(ii) Singleton Set
(iii) Finite Set
(iv) Infinite Set
(v) Equal Sets
(a) Contains only one element
(b) Has a definite number of elements
(c) Have exactly the same elements
(d) Contains no elements
(e) Does not have a definite number of elements
Answer:
Question 2. Match the sets with their cardinal numbers:
(i) $\{a, b, c\}$
(ii) $\{x : x \in \mathbb{N}, x < 5\}$
(iii) $\{0\}$
(iv) $\phi$
(v) $\{x : x^2 = 9, x \in \mathbb{R}\}$
(a) 2
(b) 0
(c) 1
(d) 3
(e) 4
Answer:
Question 3. Match the set concepts with their symbols or definitions:
(i) Proper Subset
(ii) Superset of A
(iii) Power Set of A
(iv) Universal Set
(v) Cardinality of A
(a) $P(A)$
(b) $n(A)$
(c) B if $A \subseteq B$
(d) $\subset$
(e) U
Answer:
Question 4. Match the intervals with their set-builder notation:
(i) $[a, b]$
(ii) $(a, b)$
(iii) $[a, b)$
(iv) $(a, b]$
(v) $[a, \infty)$
(a) $\{x : a < x \leq b\}$
(b) $\{x : a \leq x < b\}$
(c) $\{x : x \geq a\}$
(d) $\{x : a \leq x \leq b\}$
(e) $\{x : a < x < b\}$
Answer:
Question 5. Match the sets with their description (Type or Cardinality):
(i) Set of all lines in a plane
(ii) Set of solutions to $x^2+1=0$ in $\mathbb{R}$
(iii) $\{1, 2, 2, 3\}$
(iv) Power set of $\phi$
(v) $\{x : x \in \mathbb{N}, x^2 < 5\}$
(a) Cardinality is 2
(b) Infinite Set
(c) Empty Set
(d) Singleton Set
(e) Cardinality is 3
Answer:
Set Relations
Question 1. Match the set relation symbols with their meanings:
(i) $\subset$
(ii) $\subseteq$
(iii) $=$
(iv) $\supset$
(v) $\supseteq$
(a) Is a superset of (could be equal)
(b) Is a proper subset of
(c) Is equal to
(d) Is a subset of (could be equal)
(e) Is a proper superset of
Answer:
Question 2. Match the relation properties/components with their descriptions:
(i) Domain of R from A to B
(ii) Range of R from A to B
(iii) Codomain of R from A to B
(iv) A relation R from A to B is a subset of
(v) An ordered pair $(a, b) \in R$ means
(a) $A \times B$
(b) $\{x \in A : (x, y) \in R \text{ for some } y \in B\}$
(c) $\{y \in B : (x, y) \in R \text{ for some } x \in A\}$
(d) B
(e) $a$ is related to $b$ by R
Answer:
Question 3. Let $A = \{1, 2, 3\}$. Match the relation descriptions on A with their set forms:
(i) $R = \{(x, y) : x \text{ divides } y\}$
(ii) $R = \{(x, y) : x = y\}$
(iii) $R = \{(x, y) : x < y\}$
(iv) $R = \{(x, y) : x+y = 4\}$
(v) Universal relation
(a) $\{(1, 1), (2, 2), (3, 3)\}$
(b) $A \times A$
(c) $\{(1, 1), (1, 2), (1, 3), (2, 2), (2, 3), (3, 3)\}$
(d) $\{(1, 3), (2, 2), (3, 1)\}$
(e) $\{(1, 2), (1, 3), (2, 3)\}$
Answer:
Question 4. Let $A = \{a, b, c\}$ and $R = \{(a, a), (a, b), (b, c)\}$. Match the following:
(i) Elements in A from which arrows originate in an arrow diagram
(ii) Elements in A which are the first components of ordered pairs in R
(iii) Elements in A which are the second components of ordered pairs in R
(iv) Domain of R
(v) Range of R
(a) $\{a, b, c\}$ (All possible second components from A)
(b) $\{a, b, c\}$ (All possible first components from A)
(c) $\{a, b\}$
(d) $\{a, b\}$
(e) $\{a, b, c\}$
Answer:
Question 5. Match the number of relations:
(i) Number of relations from A to B if $n(A)=2, n(B)=3$
(ii) Number of elements in $A \times B$ if $n(A)=2, n(B)=3$
(iii) Number of subsets of $A \times B$ if $n(A \times B) = 6$
(iv) Number of possible ordered pairs $(x, y)$ if $x \in \{1, 2\}, y \in \{a, b, c\}$
(v) Number of relations on A if $n(A)=2$
(a) $2^{2 \times 3} = 2^6 = 64$
(b) $2 \times 2 = 4$ relations (on A)
(c) $2 \times 3 = 6$
(d) $2^{6}$
(e) 6
Answer:
Types of Relations
Question 1. Match the relation properties with their conditions on a set A:
(i) Reflexive
(ii) Symmetric
(iii) Transitive
(iv) Identity relation
(v) Universal relation
(a) If $(a, b) \in R$ and $(b, c) \in R$, then $(a, c) \in R$
(b) $R = A \times A$
(c) $(a, a) \in R$ for all $a \in A$
(d) If $(a, b) \in R$, then $(b, a) \in R$
(e) $R = \{(a, a) : a \in A\}$
Answer:
Question 2. Let A be the set of all triangles in a plane. Match the relations on A with their properties:
(i) $T_1 R T_2$ if $T_1$ is congruent to $T_2$
(ii) $T_1 R T_2$ if $T_1$ has more area than $T_2$
(iii) $T_1 R T_2$ if $T_1$ is perpendicular to $T_2$
(iv) $T_1 R T_2$ if $T_1$ is similar to $T_2$
(v) $T_1 R T_2$ if $T_1$ and $T_2$ have the same perimeter
(a) Symmetric only
(b) Transitive only
(c) Equivalence relation
(d) Neither reflexive, symmetric, nor transitive
(e) Equivalence relation
Answer:
Question 3. Let R be the relation on $\mathbb{Z}$ defined by $a R b$ if $a - b$ is divisible by 3. Match the following:
(i) R is
(ii) Equivalence class of 0
(iii) Equivalence class of 1
(iv) Equivalence class of 2
(v) Equivalence class of 3
(a) Equivalence relation
(b) $\{..., -2, 1, 4, ...\}$
(c) $\{..., -1, 2, 5, ...\}$
(d) $\{..., -3, 0, 3, 6, ...\}$
(e) $\{..., -3, 0, 3, 6, ...\}$
Answer:
Question 4. Match the properties to the relations on $A = \{1, 2\}$:
(i) $R_1 = \{(1, 1)\}$
(ii) $R_2 = \{(1, 2), (2, 1)\}$
(iii) $R_3 = \{(1, 1), (2, 2), (1, 2), (2, 1)\}$
(iv) $R_4 = \{(1, 1), (2, 2)\}$
(v) $R_5 = \{(1, 2)\}$
(a) Reflexive, Symmetric, Transitive (Equivalence)
(b) Neither Reflexive, Symmetric, nor Transitive
(c) Symmetric only
(d) Reflexive, Symmetric, Transitive (Identity)
(e) Symmetric, Transitive (vacuously)
Answer:
Question 5. Match the definitions with the types of relations:
(i) $R = \phi$ on a non-empty set A
(ii) $R = A \times A$ on a non-empty set A
(iii) $R = \{(a, a) : a \in A\}$ on set A
(iv) R is reflexive, symmetric, and transitive
(v) Set of all elements related to a given element $a$ by an equivalence relation
(a) Identity Relation
(b) Empty Relation
(c) Equivalence Class
(d) Universal Relation
(e) Equivalence Relation
Answer:
Set Operations and Venn Diagrams
Question 1. Match the set operations with their definitions:
(i) $A \cup B$
(ii) $A \cap B$
(iii) $A - B$
(iv) $A'$ (Complement)
(v) Symmetric Difference $A \Delta B$
(a) $\{x : x \in A \text{ and } x \notin B\}$
(b) $(A - B) \cup (B - A)$
(c) $\{x : x \in U \text{ and } x \notin A\}$
(d) $\{x : x \in A \text{ or } x \in B\}$
(e) $\{x : x \in A \text{ and } x \in B\}$
Answer:
Question 2. Let $U = \{1, 2, 3, 4, 5\}$, $A = \{1, 2, 3\}$, $B = \{3, 4\}$. Match the operations with the results:
(i) $A \cup B$
(ii) $A \cap B$
(iii) $A - B$
(iv) $B - A$
(v) $A'$
(a) $\{4, 5\}$
(b) $\{1, 2, 3, 4\}$
(c) $\{1, 2\}$
(d) $\{3\}$
(e) $\{4\}$
Answer:
Question 3. Match the Venn diagram regions (descriptions) with the set operations:
(i) Elements only in A
(ii) Elements in both A and B
(iii) Elements in A or B or both
(iv) Elements outside A
(v) Elements outside both A and B
(a) $A \cap B$
(b) $(A \cup B)'$
(c) $A \cup B$
(d) $A'$
(e) $A - B$
Answer:
Question 4. Match the set properties with the results:
(i) $A \cup \phi$
(ii) $A \cap U$
(iii) $A \cap A'$
(iv) $(A')'$
(v) $U'$
(a) $\phi$
(b) U
(c) A
(d) $\phi$
(e) A
Answer:
Question 5. Match the pairs of sets based on their relationship:
(i) Disjoint Sets
(ii) $A \subseteq B$
(iii) $A \subseteq A \cup B$
(iv) $A \cap B \subseteq A$
(v) $A - B$ and $B - A$
(a) Always true
(b) Mutually disjoint
(c) $A \cap B = \phi$
(d) $A \cup B = B$
(e) Always true
Answer:
Algebra of Sets and Cardinality Results
Question 1. Match the set properties with their names:
(i) $A \cup B = B \cup A$
(ii) $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$
(iii) $(A \cup B)' = A' \cap B'$
(iv) $A \cup A = A$
(v) $A \cup \phi = A$
(a) De Morgan's Law
(b) Idempotent Law
(c) Commutative Law
(d) Identity Law
(e) Distributive Law
Answer:
Question 2. Match the cardinality formulas with the corresponding sets for finite sets A and B:
(i) $n(A \cup B)$
(ii) $n(A \cap B)$
(iii) $n(A - B)$
(iv) $n(A \Delta B)$
(v) $n((A \cup B)')$
(a) $n(A) - n(A \cap B)$
(b) $n(A) + n(B) - n(A \cup B)$
(c) $n(A) + n(B) - 2n(A \cap B)$
(d) $n(U) - n(A \cup B)$
(e) $n(A) + n(B) - n(A \cap B)$
Answer:
Question 3. Match the descriptions from a survey with the set operations:
(i) People who like only item A
(ii) People who like A and B
(iii) People who like A or B or both
(iv) People who like neither A nor B
(v) People who like only item B
(a) $A \cap B$
(b) $A \cup B$
(c) $B - A$
(d) $(A \cup B)'$
(e) $A - B$
Answer:
Question 4. Given $n(A)=15$, $n(B)=20$, $n(A \cap B)=5$. Match the cardinalities:
(i) $n(A \cup B)$
(ii) $n(A - B)$
(iii) $n(B - A)$
(iv) $n(A \Delta B)$
(v) If $n(U)=50$, $n((A \cup B)')$ is
(a) 10
(b) 30
(c) 20
(d) 25
(e) 15
Answer:
Question 5. Match the properties of complementation:
(i) $A \cup A'$
(ii) $A \cap A'$
(iii) $(A')'$
(iv) $U'$
(v) $\phi'$
(a) $\phi$
(b) U
(c) A
(d) U
(e) $\phi$
Answer:
Functions: Definition, Domain, and Range
Question 1. Match the descriptions with the function terms:
(i) The set of all inputs for a function
(ii) The set of all possible outputs for a function (the target set)
(iii) The set of all actual outputs of a function
(iv) A special type of relation where each input has exactly one output
(v) The output value $f(x)$ for a given input $x$
(a) Function
(b) Codomain
(c) Range
(d) Domain
(e) Image
Answer:
Question 2. Let $A=\{1, 2, 3\}$, $B=\{a, b, c, d\}$. Match the relations from A to B with whether they are functions:
(i) $R_1 = \{(1, a), (2, b), (3, c)\}$
(ii) $R_2 = \{(1, a), (2, b), (1, c), (3, d)\}$
(iii) $R_3 = \{(1, a), (2, b)\}$
(iv) $R_4 = \{(1, a), (2, a), (3, a)\}$
(v) $R_5 = \{(1, a), (2, b), (3, d)\}$
(a) Not a function (element in domain has two images)
(b) Function
(c) Not a function (element in domain has no image)
(d) Function
(e) Function
Answer:
Question 3. Match the functions with their range:
(i) $f: \{1, 2, 3\} \to \mathbb{N}, f(x) = x+5$
(ii) $f: \mathbb{Z} \to \mathbb{Z}, f(x) = 2x$
(iii) $f: \mathbb{R} \to \mathbb{R}, f(x) = x^2$
(iv) $f: \mathbb{R} \to \mathbb{R}, f(x) = 7$
(v) $f: \mathbb{N} \to \mathbb{N}, f(x) = \text{largest prime factor of } x$
(a) Set of positive integers greater than 1
(b) $\{6, 7, 8\}$
(c) $\{y \in \mathbb{R} : y \geq 0\}$
(d) $\{..., -4, -2, 0, 2, 4, ...\}$
(e) $\{7\}$
Answer:
Question 4. Match the functions with their domain:
(i) $f(x) = \frac{1}{x}$ (real function)
(ii) $f(x) = \sqrt{x-2}$ (real function)
(iii) $f(x) = x^3 + 2x - 1$ (polynomial)
(iv) $f(x) = \frac{x-1}{x-1}$ (real function)
(v) $f(x) = \sqrt{4-x^2}$ (real function)
(a) $\mathbb{R}$
(b) $\mathbb{R} - \{0\}$
(c) $[2, \infty)$
(d) $[-2, 2]$
(e) $\mathbb{R} - \{1\}$
Answer:
Question 5. Match the definitions related to functions:
(i) For $(a, b) \in f$, 'a' is the
(ii) For $(a, b) \in f$, 'b' is the
(iii) The set of all first elements of ordered pairs in a function
(iv) The set of all second elements of ordered pairs in a function
(v) The set B in $f: A \to B$
(a) Range
(b) Codomain
(c) Domain
(d) Image
(e) Pre-image
Answer:
Types of Functions
Question 1. Match the function types with their definitions:
(i) Injective
(ii) Surjective
(iii) Bijective
(iv) Many-to-one
(v) Into
(a) Range is a proper subset of the codomain
(b) Different elements in domain have different images
(c) Range is equal to the codomain
(d) Both injective and surjective
(e) At least two elements in domain have the same image
Answer:
Question 2. Match the functions from $\mathbb{R} \to \mathbb{R}$ with their type:
(i) $f(x) = 5x - 2$
(ii) $f(x) = x^2$
(iii) $f(x) = \sin x$
(iv) $f(x) = x^3$
(v) $f(x) = |x|$
(a) Bijective
(b) Many-to-one and Into
(c) Bijective
(d) Many-to-one and Into
(e) Many-to-one and Into
Answer:
Question 3. Let $A=\{1, 2\}$, $B=\{a, b, c\}$. Match the possible function types for $f: A \to B$:
(i) Injective
(ii) Surjective
(iii) Bijective
(iv) Into
(v) Many-to-one
(a) Possible
(b) Not Possible ($n(A) < n(B)$)
(c) Possible ($n(A) < n(B)$)
(d) Not Possible ($n(A) \neq n(B)$)
(e) Possible
Answer:
Question 4. Let $A=\{1, 2, 3\}$, $B=\{p, q\}$. Match the possible function types for $f: A \to B$:
(i) Injective
(ii) Surjective
(iii) Bijective
(iv) Into
(v) Many-to-one
(a) Possible ($n(A) > n(B)$)
(b) Not Possible ($n(A) > n(B)$)
(c) Possible
(d) Not Possible ($n(A) \neq n(B)$)
(e) Not Possible ($n(A) > n(B)$)
Answer:
Question 5. Match the properties for finite sets A and B with function types $f: A \to B$:
(i) $n(A) = n(B)$, f is injective
(ii) $n(A) > n(B)$, f is always
(iii) $n(A) < n(B)$, f is always
(iv) $n(A) = n(B)$, f is surjective
(v) $n(A) = n(B)$, f is bijective
(a) Into
(b) Bijective
(c) Onto
(d) Many-to-one
(e) Onto
Answer:
Real Functions and Their Graphs
Question 1. Match the real functions with their typical graphs:
(i) $f(x) = c$ (Constant function)
(ii) $f(x) = x$ (Identity function)
(iii) $f(x) = x^2$ (Square function)
(iv) $f(x) = x^3$ (Cube function)
(v) $f(x) = |x|$ (Modulus function)
(a) A V-shaped graph opening upwards from the origin
(b) A line passing through the origin with slope 1
(c) A horizontal line
(d) A parabola opening upwards from the origin
(e) A curve symmetric about the origin, passing through (0,0), (1,1), (-1,-1)
Answer:
Question 2. Match the real functions with their domain:
(i) $f(x) = \frac{1}{x}$ (real function)
(ii) $f(x) = \sqrt{x}$ (real function)
(iii) $f(x) = \frac{1}{x-5}$ (real function)
(iv) $f(x) = \sin x$
(v) $f(x) = \tan x$
(a) $[0, \infty)$
(b) $\mathbb{R}$
(c) $\mathbb{R} - \{x : x = (2n+1)\pi/2, n \in \mathbb{Z}\}$
(d) $\mathbb{R} - \{5\}$
(e) $\mathbb{R}$
Answer:
Question 3. Match the real functions with their range:
(i) $f(x) = 2x + 3$
(ii) $f(x) = x^2 - 4$
(iii) $f(x) = |x| + 1$
(iv) $f(x) = -x^2$
(v) $f(x) = \cos x$
(a) $[-1, 1]$
(b) $[1, \infty)$
(c) $\mathbb{R}$
(d) $(-\infty, 0]$
(e) $[-4, \infty)$
Answer:
Question 4. Match the characteristics of graphs with the tests:
(i) Graph represents a function
(ii) Graph represents a one-to-one function
(iii) Graph represents an onto function (given codomain)
(iv) X-coordinates on the graph form the domain
(v) Y-coordinates on the graph form the range
(a) Horizontal extent
(b) Every horizontal line intersects at most once
(c) Vertical line test
(d) Vertical extent
(e) Horizontal line test
Answer:
Question 5. Match the piecewise functions with their values at specified points:
(i) $f(x) = \begin{cases} x+1 & , & x < 0 \\ x^2 & , & x \geq 0 \end{cases}$, $f(-2)$ is
(ii) $f(x) = \begin{cases} x+1 & , & x < 0 \\ x^2 & , & x \geq 0 \end{cases}$, $f(3)$ is
(iii) $g(x) = \begin{cases} 2x & , & x \leq 1 \\ 3x+1 & , & x > 1 \end{cases}$, $g(1)$ is
(iv) $g(x) = \begin{cases} 2x & , & x \leq 1 \\ 3x+1 & , & x > 1 \end{cases}$, $g(2)$ is
(v) $h(x) = |x-1|$, $h(-1)$ is
(a) 9
(b) -1
(c) 7
(d) 2
(e) 2
Answer:
Operations on Functions
Question 1. Let $f(x) = x+2$ and $g(x) = x^2$. Match the algebraic operations:
(i) $(f+g)(x)$
(ii) $(f-g)(x)$
(iii) $(fg)(x)$
(iv) $(f/g)(x)$
(v) $(gf)(x)$
(a) $x^3 + 2x^2$
(b) $x+2+x^2$
(c) $\frac{x+2}{x^2}$
(d) $x+2-x^2$
(e) $(x+2)x^2$
Answer:
Question 2. Let $f(x) = 2x$ and $g(x) = x+1$. Match the compositions:
(i) $(f \circ g)(x)$
(ii) $(g \circ f)(x)$
(iii) $(f \circ f)(x)$
(iv) $(g \circ g)(x)$
(v) $(f \circ g)(3)$
(a) $2x+1$
(b) 8
(c) $2x+2$
(d) $4x$
(e) $x+2$
Answer:
Question 3. Match the functions with the domain of the result of the operation:
(i) $f(x) = x^2, g(x) = \sqrt{x}$, domain of $(f+g)(x)$
(ii) $f(x) = \frac{1}{x}, g(x) = x-1$, domain of $(fg)(x)$
(iii) $f(x) = \sqrt{x}, g(x) = x-2$, domain of $(f/g)(x)$
(iv) $f(x) = \frac{1}{x-1}, g(x) = x+2$, domain of $(g \circ f)(x)$
(v) $f(x) = x^2+1$, domain of $(f \circ f)(x)$
(a) $[0, \infty) - \{2\}$
(b) $\mathbb{R} - \{1\}$
(c) $[0, \infty)$
(d) $\mathbb{R} - \{0, 1\}$
(e) $\mathbb{R}$
Answer:
Question 4. Match the properties of function operations:
(i) $(f+g)(x) = (g+f)(x)$ is the ______ property.
(ii) $(f \cdot g) \cdot h = f \cdot (g \cdot h)$ is the ______ property.
(iii) $f \circ (g \circ h) = (f \circ g) \circ h$ is the ______ property.
(iv) $f \circ g = g \circ f$ is the ______ property.
(v) Domain of $(f+g)$ is $D_f \cap D_g$ is a ______ property.
(a) Not generally true (not commutative)
(b) Associative (for multiplication)
(c) Commutative (for addition)
(d) Associative (for composition)
(e) Domain property
Answer:
Question 5. Let $f(x) = x-1$ and $g(x) = x+1$. Match the results:
(i) $(f \circ g)(x)$
(ii) $(g \circ f)(x)$
(iii) $(f \circ f)(x)$
(iv) $(g \circ g)(x)$
(v) $(f \circ g)(0)$
(a) $x+2$
(b) $x-2$
(c) $x$
(d) 1
(e) x
Answer:
Invertible Functions and Binary Operations
Question 1. Match the function types with invertibility conditions:
(i) Injective only
(ii) Surjective only
(iii) Bijective
(iv) Existence of $g: Y \to X$ with $f \circ g = I_Y, g \circ f = I_X$
(v) Unique image for each element in domain
(a) Condition for function
(b) Function is invertible
(c) May or may not be invertible
(d) May or may not be invertible
(e) Function is invertible
Answer:
Question 2. Match the invertible functions with their inverses:
(i) $f(x) = x+5$
(ii) $f(x) = 3x$
(iii) $f(x) = x^3$
(iv) $f(x) = \frac{1}{x}$ (for $x \neq 0$)
(v) $f(x) = 2x - 1$
(a) $f^{-1}(x) = x-5$
(b) $f^{-1}(x) = \sqrt[3]{x}$
(c) $f^{-1}(x) = x/3$
(d) $f^{-1}(x) = \frac{x+1}{2}$
(e) $f^{-1}(x) = 1/x$
Answer:
Question 3. Match the binary operation properties with their conditions on a set S with operation $*$:
(i) Closure
(ii) Commutativity
(iii) Associativity
(iv) Identity element $e$
(v) Inverse element $b$ for $a$
(a) $a * b = b * a$ for all $a, b \in S$
(b) $a * e = a$ and $e * a = a$ for all $a \in S$
(c) $(a * b) * c = a * (b * c)$ for all $a, b, c \in S$
(d) $a * b \in S$ for all $a, b \in S$
(e) $a * b = e$ and $b * a = e$
Answer:
Question 4. Match the sets and operations with their identity elements:
(i) $\mathbb{Z}$ under addition (+)
(ii) $\mathbb{Z}$ under multiplication ($\times$)
(iii) Set of all $2 \times 2$ matrices under matrix addition
(iv) Set of all $2 \times 2$ matrices under matrix multiplication
(v) $\mathbb{R}^*$ (non-zero reals) under multiplication ($\times$)
(a) $\begin{bmatrix}0 & 0 \\ 0 & 0 \end{bmatrix}$
(b) 1
(c) 0
(d) $\begin{bmatrix}1 & 0 \\ 0 & 1 \end{bmatrix}$
(e) 1
Answer:
Question 5. Match the sets and operations with properties they satisfy:
(i) $\mathbb{Z}$ under addition (+)
(ii) $\mathbb{N}$ under subtraction (-)
(iii) $\mathbb{R}$ under $a * b = \max(a, b)$
(iv) $\mathbb{R}$ under $a * b = a - b$
(v) $\mathbb{Q}$ under $a * b = \frac{a+b}{2}$
(a) Commutative and Associative
(b) Not closed on $\mathbb{N}$
(c) Commutative but not Associative
(d) Not Commutative
(e) Commutative and Associative (e.g., identity 0)
Answer: