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JEE Functions Questions

Sets, Relations and Functions is a foundational chapter in JEE Mathematics that introduces the formal language used across the entire syllabus. It defines sets and their operations, establishes how elements can be related, and introduces functions as structured mappings between sets. Because the concepts here appear implicitly in almost every other mathematics chapter, JEE Sets, Relations and Functions questions are a regular and rewarding feature of JEE Main and JEE Advanced. This chapter covers the language and operations of sets, types of relations and their properties, types of functions, domain and range, composition and inverse of functions, and binary operations. JEE Main typically tests function types, domain-range problems, and composition, while JEE Advanced may probe deeper properties of relations and bijections. Practising topic-wise questions on Cracku JEE Questions helps you recognise the standard question formats and apply definitions precisely.

Question 1 JEE Mains

Let f be a function such that $$3f(x)+2f \left(\frac{m}{19x}\right) = 5x, x\neq 0$$, where $$m= \sum_{i-1}^9(i)^{2}$$. Then f(5) - f(2) is equal to

Question 2 JEE Mains

Let $$f: \mathbb{R} \to \mathbb{R}$$ be defined as $$f(x) = \dfrac{2x^2 - 3x + 2}{3x^2 + x + 3}$$. Then $$f$$ is :

Question 3 JEE Mains

Let $$f:[1,\infty) \to [1,\infty)$$ be defined by $$f(x) = (x-1)^4 + 1$$. among the two statements:
(I) The Set $$S = \{x \in [1,\infty) : f(x) = f^{-1}(x)\}$$ contains  exactly two elements and 
(II) The Set $$S = \{x \in [1,\infty) : f(x) = f^{-1}(x+1)\}$$ is an empty set,

Question 4 JEE Mains

Let the domain of the function f(x) = $$\log_{3}\log_{5}(7-\log_{2}(x^{2}-10x+85))+\sin^{-1}\left(|\frac{3x-7}{17-x}|\right)$$ be $$(\alpha, \beta)$$. Then $$\alpha + \beta$$ is equal to :

Question 5 JEE Mains

Let $$f(x)= [x]^{2}-[x+3]-3, x\in \mathbb R$$, where $$[\cdot]$$ is the greatest integer funtion. Then

Question 6 JEE Mains

If the domain of the function $$ \large f(x)=\sin ^{-1} \left( \frac{5-x}{3+2x} \right)+\frac{1}{\log_{e}{(10-x)}} $$ is $$ \large (-\infty,\propto] \cup [\beta,\gamma) - \left\{ \delta\right\} $$, then $$ \large 6(\alpha+ \beta+ \gamma+\delta) $$ is equal to

Question 7 JEE Mains

Let for some $$\alpha \in \mathbb{R}$$ $$f : \mathbb{R} \to \mathbb{R}$$ be a function  satisfying  $$f(x+y) = f(x) + 2y^2 + y + \alpha xy$$ for all $$x, y \in \mathbb{R}$$. If $$f(0) = -1$$ and $$f(1) = 2$$, then the value of $$\displaystyle\sum_{n=1}^{5}(\alpha + f(n))$$ is  :

Question 8 JEE Mains

The number of elements in the relation $$R= \left\{(x,y): 4x^{2}+y^{2}<52,x,y\in Z\right\}$$ is

Question 9 JEE Mains

The number of strictly increasing functions f from the set {1, 2, 3, 4, 5, 6} to the set {1, 2, 3, ... , 9} such that $$f(i)\neq i \text{ for }1\leq i\leq 6$$, is equal to:

Question 10 JEE Mains

Given below are two statements :

Statement I : The function $$f:R\rightarrow R $$ defined by $$f(x)=\frac{x}{1+\mid x\mid}$$ is one-one.

Statement II : The function $$f:R\rightarrow R $$ defined by $$f(x)=\frac{x^{2}+4x-30}{x^{2}-8x+18}$$ is many-one.

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

Question 11 JEE Mains

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

Question 12 JEE Mains

If the set of all solutions of $$|x^2 + x - 9| = |x| + |x^2 - 9|$$ is $$[\alpha, \beta] \cup [\gamma, \infty)$$, then $$(\alpha^2 + \beta^2 + \gamma^2)$$ is equal to :

Question 13 JEE Mains

Let $$S=\left\{x^{3}+ax^{2}+bx+c:a,b,c, \in N \text{ and }a,b,c \leq 20\right\}$$ be a set of polynomials. Then the number of polynomials in S, which are divisible by $$x^{2}+2$$, is

Question 14 JEE Mains

If the domain of the function $$f(x)=\sqrt{\log_{0.6}\left(\left|\frac{2x-5}{x^2-4}\right|\right)}$$ is $$(-\infty, a] \cup \{b\} \cup [c, d) \cup (e, \infty)$$, then the value of $$a + b + c + d + e$$ is __________.

Question 15 JEE Mains

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

Question 16 JEE Mains

Let $$f$$ be a polynomial function such that $$\log_2(f(x)) = \left\lfloor \log_2\left(2 + \frac{2}{3} + \frac{2}{9} + \ldots \infty\right) \right\rfloor \cdot \log_3\left(1 + \frac{f(x)}{f\left(\frac{1}{x}\right)}\right)$$, $$x > 0$$ and $$f(6) = 37$$. Then $$\sum_{n=1}^{10} f(n)$$ is equal to __________.

Question 17 JEE Mains

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

Question 18 JEE Advanced

Let $$\mathbb{N}$$ denote the set of all positive integers. Consider the sets

$$A=\{1,2,3,4,5\}\quad\text{and}\quad B=\{1,2,3,4,5,6,7\}.$$

Let $$S$$ be the set of all functions $$f:A\to B$$ such that $$f(2)\neq 2$$ and $$f(4)\neq 4$$. Consider the set

$$T=\big\{f\in S:\text{there exists a function }g:B\to\mathbb{N}\text{ such that }g\big(f(x)\big)=2^x\text{ for all }x\in A\big\}.$$

Then the number of elements in the set $$T$$ is ___.

Question 19 JEE Mains

The number of the real solutions of the equation:
$$x|x+3|+|x-1|-2=0$$ is

Question 20 JEE Mains

Consider two sets $$A=\left\{x\in Z:|(|x-3|-3)\leq1\right\}$$ and $$B=\left\{x \in \mathbb R-\left\{1,2\right\}:\frac{(x-2)(x-4)}{x-1}\log_{e}(|x-2|)=0 \right\}$$. Then the number of onto functions $$f:A\rightarrow B$$ is equal to

Question 21 JEE Mains

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

Question 22 JEE Mains

If the domain of the function $$f(x)=\log_{(10x^{2}-17x+7)}{(18x^{2}-11x+1)}$$ is $$(-\infty ,a)\cup (b,c)\cup (d,\infty)-{e}$$ and 90(a + b + c + d + e) equals:

Sets, Relations and Functions Topic Overview

ParameterDetails
Topic NameSets, Relations and Functions
SubjectMathematics
JEE Main Weightage~3-5% (1-2 questions on average)
JEE Advanced Weightage~3-5% (conceptual and proof-based)
Difficulty LevelEasy to Moderate
Important ConceptsSet Operations, Types of Relations, Types of Functions, Domain and Range, Composition
Recommended Practice LevelHigh - attempt 60+ mixed problems

Why Practice JEE Sets, Relations and Functions Questions?

  • Conceptual foundation: The language of sets and functions underlies every other Mathematics chapter.
  • Reliable weightage: This chapter contributes 1-2 questions in JEE Main consistently.
  • Definitional scoring: Questions reward precise understanding of definitions rather than heavy computation.
  • Domain-range variety: Function problems appear in many forms across the JEE paper.
  • Composition and inverse focus: These subtopics yield direct and predictable question patterns.
  • Builds logical precision: Reasoning about injectivity and surjectivity sharpens analytical thinking.
  • Efficient to master: A compact set of definitions covers the entire chapter.

Important Concepts and Subtopics

ConceptImportanceDifficulty LevelFrequently Asked In
Set Operations and LawsHighEasyJEE Main
Types of RelationsVery HighEasy-ModerateJEE Main and Advanced
Equivalence RelationsHighModerateJEE Main and Advanced
Types of Functions (Injective, Surjective, Bijective)Very HighModerateJEE Main and Advanced
Domain and Range of FunctionsVery HighModerateJEE Main
Composition of FunctionsVery HighModerateJEE Main and Advanced
Inverse FunctionsHighModerateJEE Main and Advanced
Binary OperationsModerateModerateJEE Main

Preparation Strategy for JEE Sets, Relations and Functions

Concept learning: Begin by mastering the definitions of set operations and their properties, including De Morgan's laws. Move to relations, focusing on reflexivity, symmetry, and transitivity as the conditions for equivalence relations. Then study functions systematically, learning to identify injectivity and surjectivity from a rule, graph, or table.

Formula revision: Keep the cardinality formulas for unions and intersections, the conditions for each function type, and the rules for domain determination together for quick review. Well-organised JEE Study Material helps you keep these definitions and worked examples in one place so recalling the right condition under exam pressure becomes automatic.

Problem-solving techniques: For domain questions, identify all conditions that restrict the input simultaneously and intersect them. For composition questions, substitute one function into the other carefully, tracking the domain at each step. For relation questions, test all three properties systematically before concluding the type.

Common mistakes: Missing a restriction when finding the domain, confusing injective with surjective, testing only some pairs when verifying symmetry, and forgetting that a function must assign exactly one output to each input.

Exam strategy: Attempt direct function-type and domain-range questions first for quick marks, then handle composition and equivalence-relation problems that need more careful reasoning.

JEE Main and Advanced Weightage Analysis

ExamAverage QuestionsExpected Marks
JEE Main1-24-8
JEE Advanced1-2 (conceptual)4-8

Sets, Relations and Functions is a steady contributor in JEE Main through function-type and domain-range questions. In JEE Advanced, it tends to appear in more conceptual or proof-adjacent problems that test the precise understanding of bijections and equivalence classes.

Tips to Solve Sets, Relations and Functions Questions Faster

  • For domain problems, identify all constraints simultaneously and intersect their solution sets.
  • Test injectivity by assuming f(a) equals f(b) and checking whether a must equal b.
  • Test surjectivity by assuming an arbitrary output and checking whether a valid input exists.
  • Use the Venn-diagram representation to verify set-operation identities quickly.
  • For equivalence relations, check all three properties systematically in the given order.
  • For composite functions, track the domain restriction from inner to outer function carefully.

Practising these in timed conditions with a JEE Mock Test sharpens the definitional precision this chapter rewards and builds the reading accuracy needed across the full Mathematics paper.

Frequently Asked Questions