Math · Sets, Relations and Functions

Sets formulas for JEE

Every Sets formula you need for JEE, grouped by concept.

34 formulas3 concepts
01

Subsets and Power Sets

4 formulas

Set Equality Condition

AB and BA    A=BA \subset B \text{ and } B \subset A \iff A = B

Two sets are equal if and only if they are subsets of each other.

setsequalitysubsets

Length of an Interval

L=baL = b - a

The length of any interval bounded by a and b on the real number line.

applies whena<ba < b
setsintervalslength

Power set size

P(A)=2A|P(A)|=2^{|A|}

The number of subsets in a power set for a finite set A.

applies whenSet A must be finite.
setspowersetcardinalityjee

Subset Condition

aA    aBa \in A \implies a \in B

Definition of a subset; every element of A is also in B.

applies whenA is a subset of B (ABA \subset B).
setssubsetsdefinition
02

Set Operations

21 formulas

Absorption Law (Intersection)

A(AB)=AA \cap (A \cup B) = A

The intersection of a set with its union with another set is the set itself.

setsabsorptionintersectionidentities

Absorption Law (Union)

A(AB)=AA \cup (A \cap B) = A

The union of a set with its intersection with another set is the set itself.

setsabsorptionunionidentities

Set Decomposition

A=(AB)(AB)A = (A \cap B) \cup (A - B)

A set A can be partitioned into its intersection with B and its difference from B.

setsdecompositiondifference

Difference of Sets

AB={x:xA and xB}A - B = \{x : x \in A \text{ and } x \notin B\}

Set of elements which belong to A but not to B.

setsoperationsdifference

Distributive Law

A(BC)=(AB)(AC)A \cap (B \cup C) = (A \cap B) \cup (A \cap C)

Intersection distributes over union.

setsintersectionuniondistributive

Associative Law (Intersection)

(AB)C=A(BC)(A \cap B) \cap C = A \cap (B \cap C)

The grouping of sets does not matter for intersection.

setsintersectionassociative

Commutative Law (Intersection)

AB=BAA \cap B = B \cap A

The order of sets does not matter for intersection.

setsintersectioncommutative

Idempotent Law (Intersection)

AA=AA \cap A = A

The intersection of a set with itself is the set itself.

setsintersectionidempotent

Law of U (Intersection)

UA=AU \cap A = A

The intersection of any set with the universal set is the set itself.

setsintersectionidentity

Intersection of Sets

AB={x:xA and xB}A \cap B = \{x : x \in A \text{ and } x \in B\}

Set of all elements which are common to both A and B.

setsoperationsintersection

Law of Empty Set (Intersection)

ϕA=ϕ\phi \cap A = \phi

The intersection of any set with the empty set is the empty set.

setsintersectionempty_set

Symmetric Difference

AΔB=(AB)(BA)A \Delta B = (A - B) \cup (B - A)

Set of elements that belong to exactly one of the sets A or B.

setssymmetric_differencejee

Associative Law (Union)

(AB)C=A(BC)(A \cup B) \cup C = A \cup (B \cup C)

The grouping of sets does not matter for union.

setsunionassociative

Commutative Law (Union)

AB=BAA \cup B = B \cup A

The order of sets does not matter for union.

setsunioncommutative

Union of Sets

AB={x:xA or xB}A \cup B = \{x : x \in A \text{ or } x \in B\}

Set consisting of all elements that are either in A, in B, or in both.

setsoperationsunion

Union with Difference Identity

A(BA)=ABA \cup (B - A) = A \cup B

The union of A and the elements strictly in B but not A equals the union of A and B.

setsuniondifferenceidentities

Idempotent Law (Union)

AA=AA \cup A = A

The union of a set with itself is the set itself.

setsunionidempotent

Law of Identity Element (Union)

Aϕ=AA \cup \phi = A

The union of any set with the empty set is the set itself.

setsunionidentity

Union size

AB=A+BAB|A\cup B|=|A|+|B|-|A\cap B|

Principle of inclusion-exclusion for the cardinality of the union of two sets.

applies whenSets A and B must be finite.
setscardinalityinclusion_exclusionjee

Union Size (3 Sets)

ABC=A+B+CABBCAC+ABC|A \cup B \cup C| = |A| + |B| + |C| - |A \cap B| - |B \cap C| - |A \cap C| + |A \cap B \cap C|

Principle of inclusion-exclusion for the cardinality of three intersecting finite sets.

applies whenSets A, B, and C must be finite.
setscardinalityinclusion_exclusionjee

Law of U (Union)

UA=UU \cup A = U

The union of the universal set with any of its subsets is the universal set.

setsunionuniversal
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03

Properties of Complement Sets

9 formulas

Complement size

Ac=UA|A^c|=|U|-|A|

Cardinality of complement in universal set.

applies whenFinite universal set U.
setcardinality

Complement of a Set

A={x:xU and xA}A' = \{x : x \in U \text{ and } x \notin A\}

Set of all elements of the universal set which are not elements of A.

setscomplementdefinition

Complement Difference Relation

A=UAA' = U - A

The complement of A is the difference between the universal set and A.

setscomplementdifference

Complement Law (Intersection)

AA=ϕA \cap A' = \phi

The intersection of a set and its complement is the empty set.

setscomplementintersection

Complement Law (Union)

AA=UA \cup A' = U

The union of a set and its complement is the universal set.

setscomplementunion

De Morgan's Laws

(AB)=AB, (AB)=AB(A \cup B)' = A' \cap B', \ (A \cap B)' = A' \cup B'

The complement of the union/intersection of two sets is the intersection/union of their complements.

setsdemorgancomplement

Law of Double Complementation

(A)=A(A')' = A

The complement of the complement of a set is the set itself.

setscomplementdouble

Law of Empty Set Complement

ϕ=U\phi' = U

The complement of the empty set is the universal set.

setscomplementempty_set

Law of Universal Set Complement

U=ϕU' = \phi

The complement of the universal set is the empty set.

setscomplementuniversal_set
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