Maths · Class 11 · Chapter 2
Relations and Functions
10 lessons 97 min 2 simulations
This chapter builds functions from the ground up: ordered pairs, the Cartesian product of two sets, relations as subsets of that product, and functions as the relations in which every input has exactly one output. It then studies the standard real functions with their graphs, domains and ranges, and the arithmetic of combining functions, all of which calculus depends on.
What the exam asks
JEE Main asks for n(A × B) and the number of relations 2^(pq), whether a given set of pairs is a function, and above all the domain and range of real functions, including |x|, the signum function and the greatest integer function [x]. Marks are lost by treating A × B as equal to B × A, by writing [−2.4] = −2, by forgetting that a denominator cannot vanish or that √ needs a non-negative input, and by giving the codomain when the range was asked.
Lessons
10 lessons · 97 min
1Ordered pairs and the Cartesian productNCERT §2.28 min2Working with Cartesian productsNCERT §2.29 min3RelationsNCERT §2.38 min4FunctionsNCERT §2.412 min 1 sim5Identity, constant and polynomial functionsNCERT §2.4.18 min6Rational and modulus functionsNCERT §2.4.18 min7Signum and greatest integer functionsNCERT §2.4.112 min 1 sim8Domain and range of real functionsNCERT §2.49 min9Algebra of real functionsNCERT §2.4.28 min10Chapter reviewMust-know facts, traps and formulas15 min