CBSE Class 11 Maths Revision Notes

CBSE Class 11 Maths Revision Notes summarise the important concepts, formulas and methods covered across the current 14-chapter syllabus. They help students revise algebra, trigonometry, coordinate geometry, calculus, statistics and probability in a structured form.

Class 11 Mathematics introduces concepts that form the base for higher-level Mathematics. Students study sets, functions, trigonometry, algebra, coordinate geometry, introductory calculus, statistics and probability.

These CBSE Class 11 Maths Revision Notes follow the current 2026–27 NCERT chapter order. Use them to recall definitions, understand formulas and revise the main methods required for solving textbook questions.

Key Takeaways

• 14 chapters: The current Class 11 Mathematics textbook contains 14 main chapters.
• Five broad areas: The syllabus covers sets and functions, algebra, coordinate geometry, calculus, and statistics and probability.
• Current chapter order: Complex Numbers is Chapter 4, while Probability is Chapter 14.
• Rationalised content: Mathematical Induction and Mathematical Reasoning are not separate chapters in the current textbook.

Access CBSE Class 11 Maths Revision Notes in 30 Minutes

Revise the syllabus in three parts:

• First 10 minutes: Sets, relations, functions, trigonometric functions and complex numbers
• Next 10 minutes: Linear inequalities, permutations, combinations, binomial theorem, sequences and series
• Final 10 minutes: Straight lines, conic sections, three-dimensional geometry, limits, derivatives, statistics and probability

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Chapter-Wise CBSE Class 11 Mathematics Notes

The current Class 11 Mathematics textbook contains 14 chapters. The chapters move from basic set concepts to algebra, geometry, calculus, statistics and probability.

Chapter 1: Sets

A set is a well-defined collection of objects. Objects belonging to a set are called its elements.

This chapter covers roster form, set-builder form, empty sets, finite sets, infinite sets and equal sets. Students also study subsets, universal sets and Venn diagrams.

The main set operations are union, intersection, difference and complement.

Important notation:

• x ∈ A means x belongs to set A.
• x ∉ A means x does not belong to set A.
• A ⊆ B means A is a subset of B.
• A ∪ B represents the union of A and B.
• A ∩ B represents the intersection of A and B.
• A′ represents the complement of A.

Chapter 2: Relations and Functions

A Cartesian product contains ordered pairs formed from two sets. If A and B are non-empty sets, then:

A × B = {(a, b): a ∈ A and b ∈ B}

A relation from A to B is a subset of A × B. The first elements form the domain, while the related second elements form the range.

A function assigns each element of its domain to exactly one element in its codomain. Students learn to identify functions and represent them mathematically.

Chapter 3: Trigonometric Functions

This chapter extends trigonometry beyond acute angles. Angles are measured in degrees and radians.

The relation between degree and radian measure is:

180° = π radians

Therefore:

1 radian = 180°/π
1° = π/180 radians

Students study the signs and values of trigonometric functions in different quadrants. The chapter also covers functions involving the sum and difference of two angles.

Important formulas include:

sin (x + y) = sin x cos y + cos x sin y

sin (x − y) = sin x cos y − cos x sin y

cos (x + y) = cos x cos y − sin x sin y

cos (x − y) = cos x cos y + sin x sin y

Chapter 4: Complex Numbers and Quadratic Equations

A complex number is written as:

z = a + ib

Here, a and b are real numbers, and i² = −1.

The real part of z is a, while the imaginary part is b. Complex numbers allow students to work with square roots of negative numbers.

Students learn addition, subtraction and multiplication of complex numbers. The chapter also introduces modulus, conjugate, the Argand plane and polar representation.

For z = a + ib:

Conjugate of z = a − ib

|z| = √(a² + b²)

Chapter 5: Linear Inequalities

An inequality compares two quantities using symbols such as <, >, ≤ and ≥.

Students learn to solve linear inequalities in one variable. The solution can also be shown on a number line.

When an inequality is multiplied or divided by a negative number, its sign reverses.

For example:

−2x > 6

Dividing both sides by −2 gives:

x < −3

The direction changes from greater than to less than.

Chapter 6: Permutations and Combinations

The fundamental principle of counting helps determine the total number of possible outcomes.

If one operation can occur in m ways and another in n ways, both operations can occur in:

m × n ways

A permutation is an arrangement in which order matters.

nPr = n!/(n − r)!

A combination is a selection in which order does not matter.

nCr = n!/[r!(n − r)!]

The relation between them is:

nPr = r! × nCr

Chapter 7: Binomial Theorem

The binomial theorem gives a systematic expansion of expressions such as (a + b)ⁿ.

For a positive integer n:

(a + b)ⁿ = nC0aⁿ + nC1aⁿ⁻¹b + nC2aⁿ⁻²b² + ... + nCnbⁿ

The general term is:

Tr+1 = nCr aⁿ⁻ʳbʳ

Students use this expression to identify a required term without expanding the complete expression.

The coefficients in a binomial expansion are called binomial coefficients. They are obtained using combinations.

Chapter 8: Sequences and Series

A sequence is an ordered list of numbers. A series is formed by adding the terms of a sequence.

A geometric progression has a constant ratio between consecutive terms.

If a is the first term and r is the common ratio, then the nth term is:

an = arⁿ⁻¹

The sum of the first n terms is:

Sn = a(rⁿ − 1)/(r − 1), when r ≠ 1

The chapter also explains the relationship between arithmetic mean and geometric mean.

For two positive numbers a and b:

AM = (a + b)/2

GM = √ab

AM ≥ GM

Chapter 9: Straight Lines

The slope of a line shows its inclination.

For points (x1, y1) and (x2, y2):

m = (y2 − y1)/(x2 − x1)

The point-slope form of a line is:

y − y1 = m(x − x1)

The slope-intercept form is:

y = mx + c

The intercept form is:

x/a + y/b = 1

Students also learn the angle between two lines and the distance of a point from a line.

For the line Ax + By + C = 0, the distance of point (x1, y1) is:

|Ax1 + By1 + C|/√(A² + B²)

Chapter 10: Conic Sections

Conic sections are curves obtained when a plane intersects a double-napped cone.

The four main conic sections are:

• Circle
• Parabola
• Ellipse
• Hyperbola

The standard equation of a circle with centre at the origin is:

x² + y² = r²

The standard equation of a parabola is:

y² = 4ax

The standard equation of an ellipse is:

x²/a² + y²/b² = 1

The standard equation of a hyperbola is:

x²/a² − y²/b² = 1

Students study the standard forms and important elements of these curves.

Chapter 11: Introduction to Three Dimensional Geometry

Three-dimensional geometry uses three mutually perpendicular coordinate axes.

A point in space is represented as:

P(x, y, z)

The coordinate planes are:

• XY-plane
• YZ-plane
• ZX-plane

The distance between P(x1, y1, z1) and Q(x2, y2, z2) is:

PQ = √[(x2 − x1)² + (y2 − y1)² + (z2 − z1)²]

This formula extends the two-dimensional distance formula to three-dimensional space.

Chapter 12: Limits and Derivatives

A limit describes the value that a function approaches when the variable approaches a given value.

It is written as:

lim x→a f(x)

Students learn the algebra of limits and limits of trigonometric functions.

Important limits include:

lim x→0 sin x/x = 1

lim x→0 (1 − cos x)/x = 0

A derivative measures the rate of change of a function.

The derivative of f(x) is defined as:

f′(x) = lim h→0 [f(x + h) − f(x)]/h

Chapter 13: Statistics

Statistics in Class 11 focuses on measures of dispersion. Dispersion shows how far observations spread around a central value.

The main measures are:

• Range
• Mean deviation
• Variance
• Standard deviation

Range is calculated as:

Range = Largest value − Smallest value

Variance measures the average of squared deviations from the mean.

Standard deviation is the positive square root of variance:

Standard deviation = √Variance

A smaller standard deviation indicates that the observations are closer to the mean.

Chapter 14: Probability

A random experiment can produce different possible outcomes. The set of all possible outcomes is called the sample space.

An event is a subset of the sample space.

The axiomatic approach states:

P(A) ≥ 0

P(S) = 1

If A and B are mutually exclusive events:

P(A ∪ B) = P(A) + P(B)

The probability of the complement of A is:

P(A′) = 1 − P(A)

This chapter builds a formal understanding of probability using events and probability rules.

Major Areas Covered in Class 11 Maths Notes

The Class 11 Mathematics syllabus can be grouped into five broad areas. Each area develops a different type of mathematical thinking.

Sets, Relations and Functions

Sets introduce mathematical grouping and notation. Relations connect elements of two sets, while functions describe a fixed mapping between inputs and outputs.

These concepts support later work in algebra and calculus.

Algebra

Algebra includes complex numbers, inequalities, counting methods, binomial expansions, sequences and series.

These chapters require careful use of notation and formulas. Students also need to identify whether a problem involves arrangement, selection, expansion or progression.

Coordinate Geometry

Straight lines and conic sections deal with two-dimensional geometry. Three-dimensional geometry introduces points and distance in space.

Graphs, coordinate systems and standard equations play an important role in these chapters.

Calculus

Limits and derivatives provide an introduction to calculus.

Limits describe the value approached by a function. Derivatives measure how a function changes with respect to a variable.

Statistics and Probability

Statistics explains the spread of numerical data. Probability measures the possibility of an event.

Both chapters require correct identification of values, events and formulas before calculation.

Important Class 11 Maths Concepts and Formulas

This quick revision table brings together formulas from different chapters.

How Class 11 Maths Revision Notes Support Exam Preparation

Class 11 Mathematics requires both conceptual understanding and regular problem-solving. Revision notes help students recall the concept before they begin an exercise.

The notes can be used to:

• Review definitions before solving questions
• Recall formulas from a complete chapter
• Compare similar mathematical ideas
• Identify the correct method for a problem
• Check symbols and standard forms
• Revise several chapters before an examination

A formula alone may not be enough for every question. Students also need to understand the condition under which the formula applies.

For example, permutation is used when order matters. Combination is used when only selection matters.

Similarly, the standard equations of conic sections depend on the position of the curve and its axis. Reading the question carefully is therefore part of mathematical revision.

Class 11 Mathematics Assessment Pattern

Class 11 assessment generally includes a theory examination and internal assessment.

The exact school examination format may include objective, short-answer and long-answer questions. Internal assessment may include periodic tests and other school-based activities.

Students should follow the assessment plan shared by their school for the 2026–27 session.