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Class 11 Maths Formulas for CBSE & JEE Main 2026 – Chapterwise Formula Sheet, PDF

By rohit.pandey1

|

Updated on 26 May 2026, 16:06 IST

Mathematics in Class 11 forms the foundation for higher studies, competitive exams, and problem-solving skills required in engineering, science, economics, and technology. Whether you are preparing for CBSE Board Exams, JEE Main 2027, school tests, or Olympiads, learning formulas is one of the most important steps toward scoring high marks.

Download Class 11 Maths Formulas PDF (Free)

Chapter No.CBSE Class 11 Maths Formula ChapterFormula Resource
Chapter 1Sets Formulas Class 11View Formulas 
Chapter 2Relations and Functions Formulas Class 11View Formulas 
Chapter 3Trigonometric Functions Formulas Class 11View Formulas 
Chapter 4Principle of Mathematical Induction FormulasView Formulas 
Chapter 5Complex Numbers and Quadratic Equations FormulasView Formulas 
Chapter 7Permutations and Combinations Formulas Class 11View Formulas 
Chapter 8Binomial Theorem Formulas Class 11View Formulas 
Chapter 10Straight Lines Formulas Class 11View Formulas 
Chapter 12Three Dimensional Geometry Formulas Class 11View Formulas 
Chapter 13Limits and Derivatives Formulas Class 11View Formulas 
Chapter 14Mathematical Reasoning Formulas Class 11View Formulas 
Chapter 15Statistics Formulas Class 11View Formulas 
Chapter 16Probability Formulas Class 11View Formulas 

Chapter 1: Sets Formulas for Class 11

Important Sets Formulas and Operations

Sets form the foundation of Class 11 Maths. Here are all essential formulas:

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Basic Set Operations:

FormulaDescription
n(A ∪ B) = n(A) + n(B) - n(A ∩ B)Union of two sets
n(A ∪ B ∪ C) = n(A) + n(B) + n(C) - n(A ∩ B) - n(B ∩ C) - n(A ∩ C) + n(A ∩ B ∩ C)Union of three sets
n(A - B) = n(A) - n(A ∩ B)Difference of sets
n(A') = n(U) - n(A)Complement of a set
n(A ⊕ B) = n(A - B) + n(B - A)Symmetric difference

De Morgan's Laws:

  • (A ∪ B)' = A' ∩ B'
  • (A ∩ B)' = A' ∪ B'

Memory Tip: Remember "Union adds, Intersection subtracts" for the n(A ∪ B) formula.

Common Mistake to Avoid: Don't forget to subtract n(A ∩ B) when calculating n(A ∪ B).

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Chapter 2: Relations and Functions Formulas Class 11

Key Relations and Functions Formulas

Types of Relations:

Relation TypeDefinition
Reflexive(a, a) ∈ R for all a ∈ A
Symmetric(a, b) ∈ R ⟹ (b, a) ∈ R
Transitive(a, b) ∈ R and (b, c) ∈ R ⟹ (a, c) ∈ R
EquivalenceReflexive + Symmetric + Transitive

Function Formulas:

Domain and Range:
  • For f: A → B, Domain = A, Codomain = B
  • Range = {f(x) : x ∈ A} ⊆ B
Types of Functions:
  • One-One (Injective): f(x₁) = f(x₂) ⟹ x₁ = x₂
  • Onto (Surjective): Range = Codomain
  • Bijective: Both One-One and Onto
Composite Functions:
  • (fog)(x) = f(g(x))
  • Domain of fog = {x ∈ domain of g : g(x) ∈ domain of f}

Chapter 3: Trigonometric Functions Formulas Class 11

Complete Trigonometry Formulas for Class 11 Maths

Trigonometry is crucial for both boards and JEE. Master these formulas for scoring high.

Basic Trigonometric Ratios:

FunctionDefinitionRange
sin θOpposite/Hypotenuse[-1, 1]
cos θAdjacent/Hypotenuse[-1, 1]
tan θOpposite/Adjacent(-∞, ∞)
cot θAdjacent/Opposite(-∞, ∞)
sec θHypotenuse/Adjacent(-∞, -1] ∪ [1, ∞)
cosec θHypotenuse/Opposite(-∞, -1] ∪ [1, ∞)

Fundamental Trigonometric Identities:

Pythagorean Identities:
  • sin²θ + cos²θ = 1
  • 1 + tan²θ = sec²θ
  • 1 + cot²θ = cosec²θ
Reciprocal Identities:
  • sin θ = 1/cosec θ
  • cos θ = 1/sec θ
  • tan θ = 1/cot θ
Quotient Identities:
  • tan θ = sin θ/cos θ
  • cot θ = cos θ/sin θ

Sum and Difference Formulas:

  • sin(A + B) = sin A cos B + cos A sin B
  • sin(A - B) = sin A cos B - cos A sin B
  • cos(A + B) = cos A cos B - sin A sin B
  • cos(A - B) = cos A cos B + sin A sin B
  • tan(A + B) = (tan A + tan B)/(1 - tan A tan B)
  • tan(A - B) = (tan A - tan B)/(1 + tan A tan B)

Double Angle Formulas:

  • sin 2θ = 2 sin θ cos θ
  • cos 2θ = cos²θ - sin²θ = 2cos²θ - 1 = 1 - 2sin²θ
  • tan 2θ = 2 tan θ/(1 - tan²θ)

Triple Angle Formulas:

  • sin 3θ = 3 sin θ - 4 sin³θ
  • cos 3θ = 4 cos³θ - 3 cos θ
  • tan 3θ = (3 tan θ - tan³θ)/(1 - 3 tan²θ)

Product to Sum Formulas:

  • 2 sin A cos B = sin(A + B) + sin(A - B)
  • 2 cos A sin B = sin(A + B) - sin(A - B)
  • 2 cos A cos B = cos(A + B) + cos(A - B)
  • 2 sin A sin B = cos(A - B) - cos(A + B)

Sum to Product Formulas:

  • sin C + sin D = 2 sin[(C+D)/2] cos[(C-D)/2]
  • sin C - sin D = 2 cos[(C+D)/2] sin[(C-D)/2]
  • cos C + cos D = 2 cos[(C+D)/2] cos[(C-D)/2]
  • cos C - cos D = -2 sin[(C+D)/2] sin[(C-D)/2]

Mnemonic for sin(A+B): "Sine Add: Same Different" (sin cos + cos sin)

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Mnemonic for cos(A+B): "Cosine Add: Cosines Sines Subtract" (cos cos - sin sin)

JEE Tip: Double and triple angle formulas appear frequently in competitive exams.

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Chapter 4: Principle of Mathematical Induction

Mathematical Induction Formula and Steps

Principle of Mathematical Induction:

For a statement P(n) to be true for all natural numbers n ≥ 1:

  • Step 1: Prove P(1) is true (Base Case)
  • Step 2: Assume P(k) is true for some k ∈ N (Induction Hypothesis)
  • Step 3: Prove P(k+1) is true using P(k) (Induction Step)

Common Formulas Proved by Induction:

FormulaDescription
1 + 2 + 3 + ... + n = n(n+1)/2Sum of first n natural numbers
1² + 2² + 3² + ... + n² = n(n+1)(2n+1)/6Sum of squares
1³ + 2³ + 3³ + ... + n³ = [n(n+1)/2]²Sum of cubes

Chapter 5: Complex Numbers and Quadratic Equations Formulas

Important Complex Numbers Formulas for Class 11

Basic Complex Number Formulas:

FormulaDescription
z = a + ibStandard form (a = real part, b = imaginary part)
i² = -1Definition of iota
i³ = -i, i⁴ = 1Powers of i (cycle repeats every 4)
z̄ = a - ibConjugate of z
|z| = √(a² + b²)Modulus/Absolute value
arg(z) = tan⁻¹(b/a)Argument of z

Algebraic Operations:

  • Addition: (a + ib) + (c + id) = (a + c) + i(b + d)
  • Subtraction: (a + ib) - (c + id) = (a - c) + i(b - d)
  • Multiplication: (a + ib)(c + id) = (ac - bd) + i(ad + bc)
  • Division: (a + ib)/(c + id) = [(a + ib)(c - id)]/[c² + d²]

Important Properties:

  • z × z̄ = |z|²
  • |z₁ × z₂| = |z₁| × |z₂|
  • |z₁/z₂| = |z₁|/|z₂|
  • arg(z₁ × z₂) = arg(z₁) + arg(z₂)

Polar Form:

  • z = r(cos θ + i sin θ) where r = |z| and θ = arg(z)
  • Euler's Form: z = re^(iθ)

Quadratic Equation Formulas:

For ax² + bx + c = 0:

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  • Roots: x = [-b ± √(b² - 4ac)]/2a
  • Discriminant: D = b² - 4ac
    • D > 0: Real and distinct roots
    • D = 0: Real and equal roots
    • D < 0: Complex conjugate roots
  • Sum of roots: α + β = -b/a
  • Product of roots: αβ = c/a

Forming Quadratic Equation:

  • x² - (sum of roots)x + (product of roots) = 0
  • x² - (α + β)x + αβ = 0

Chapter 6: Linear Inequalities Formulas Class 11

Key Linear Inequalities Rules and Formulas

Basic Rules:

RuleExample
Adding/Subtracting same number to both sides doesn't change inequalityIf a < b, then a + c < b + c
Multiplying/Dividing by positive number doesn't change inequalityIf a < b and c > 0, then ac < bc
Multiplying/Dividing by negative number reverses inequalityIf a < b and c < 0, then ac > bc

Graphical Representation:

  • ax + by < c: Shade region not containing origin (if c > 0)
  • ax + by > c: Shade region containing origin (if c > 0)
  • Solid line for ≤ or ≥
  • Dashed line for < or >

Chapter 7: Permutations and Combinations Formulas Class 11

Complete Permutation and Combination Formulas

This chapter is highly scoring for both CBSE and JEE. Master these formulas.

Fundamental Principle of Counting:

  • If task A can be done in m ways and task B in n ways, total ways = m × n

Permutation Formulas:

FormulaDescriptionWhen to Use
ⁿPᵣ = n!/(n-r)!Permutations of n things taken r at a timeArrangement matters
ⁿPₙ = n!Permutations of n distinct objectsAll objects arranged
n! = n × (n-1) × (n-2) × ... × 2 × 1FactorialBasic calculation
0! = 1Zero factorialBy convention

Combination Formulas:

FormulaDescriptionWhen to Use
ⁿCᵣ = n!/[r!(n-r)!]Combinations of n things taken r at a timeSelection, order doesn't matter
ⁿCᵣ = ⁿCₙ₋ᵣSymmetry propertySimplification
ⁿCᵣ + ⁿCᵣ₋₁ = ⁿ⁺¹CᵣPascal's identityBuilding combinations
ⁿC₀ = ⁿCₙ = 1Boundary conditionsEdge cases

Relationship Between P and C:

  • ⁿPᵣ = r! × ⁿCᵣ

Special Cases:

Circular Permutations:
  • Arranging n distinct objects in a circle: (n-1)!/2
  • If direction matters: (n-1)!
Permutations with Repetition:
  • n objects where p are alike, q are alike: n!/(p! × q!)
  • Use Permutation when: "Arrange", "Order", "Rank", "Position" appear
  • Use Combination when: "Select", "Choose", "Committee", "Group" appear

Common CBSE Question Types:

  1. Forming words from letters
  2. Committee selection problems
  3. Arrangement of people in a row/circle
  4. Distribution of objects

Chapter 8: Binomial Theorem Formulas for Class 11

Important Binomial Theorem Formulas and Expansions

Binomial Theorem for Positive Integer n:

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

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General Term (Tᵣ₊₁):

  • Tᵣ₊₁ = ⁿCᵣ aⁿ⁻ʳ bʳ

Middle Terms:

  • If n is even: Middle term = T₍ₙ/₂₊₁₎
  • If n is odd: Two middle terms = T₍₍ₙ₊₁₎/₂₎ and T₍₍ₙ₊₃₎/₂₎

Important Results:

FormulaResult
(1 + x)ⁿⁿC₀ + ⁿC₁x + ⁿC₂x² + ... + ⁿCₙxⁿ
(1 - x)ⁿⁿC₀ - ⁿC₁x + ⁿC₂x² - ... + (-1)ⁿ ⁿCₙxⁿ
Coefficient of xʳ in (a + bx)ⁿⁿCᵣ aⁿ⁻ʳ bʳ

Sum of Binomial Coefficients:

  • ⁿC₀ + ⁿC₁ + ⁿC₂ + ... + ⁿCₙ = 2ⁿ
  • ⁿC₀ - ⁿC₁ + ⁿC₂ - ... + (-1)ⁿ ⁿCₙ = 0

JEE Important:

  • Greatest coefficient in (1+x)ⁿ occurs at middle term(s)
  • To find independent term: Set power of x = 0

Chapter 9: Sequences and Series Formulas Class 11

AP, GP, and HP Formulas for Class 11 Maths

Arithmetic Progression (AP) Formulas:

FormulaDescriptionExample
aₙ = a + (n-1)dnth terma=2, d=3: a₅=2+4(3)=14
Sₙ = n/2[2a + (n-1)d]Sum of n terms (Form 1)For above: S₅=5/2[4+12]=40
Sₙ = n/2[a + l]Sum of n terms (Form 2)l = last term
d = aₙ - aₙ₋₁Common differenceConstant difference

Arithmetic Mean (AM):

  • If a, A, b are in AP: A = (a+b)/2
  • n AMs between a and b: A₁, A₂, ..., Aₙ where d = (b-a)/(n+1)

Geometric Progression (GP) Formulas:

FormulaDescriptionWhen to Use
aₙ = arⁿ⁻¹nth termr = common ratio
Sₙ = a(rⁿ - 1)/(r - 1)Sum of n terms (r > 1)Finite GP
Sₙ = a(1 - rⁿ)/(1 - r)Sum of n terms (r < 1)Finite GP
S∞ = a/(1-r)Sum to infinity|r| < 1 only

Geometric Mean (GM):

  • If a, G, b are in GP: G = √(ab)
  • n GMs between a and b: G₁, G₂, ..., Gₙ where r = (b/a)^[1/(n+1)]

Harmonic Progression (HP):

  • If a, b, c are in HP, then 1/a, 1/b, 1/c are in AP
  • Harmonic Mean: H = 2ab/(a+b)

Relationship Between AM, GM, HM:

  • AM ≥ GM ≥ HM
  • GM² = AM × HM

Special Series Sums:

SeriesSum Formula
1 + 2 + 3 + ... + nn(n+1)/2
1² + 2² + 3² + ... + n²n(n+1)(2n+1)/6
1³ + 2³ + 3³ + ... + n³[n(n+1)/2]²

💡 Memory Trick for GP Sum:

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  • r > 1: "Ratio minus 1 below" → (rⁿ - 1)/(r - 1)
  • r < 1: "1 minus ratio below" → (1 - rⁿ)/(1 - r)

Chapter 10: Straight Lines Formulas Class 11

Coordinate Geometry: All Straight Line Formulas

Distance and Section Formulas:

FormulaDescriptionApplication
d = √[(x₂-x₁)² + (y₂-y₁)²]Distance between two pointsFinding length
((mx₂+nx₁)/(m+n), (my₂+ny₁)/(m+n))Section formula (internal)Dividing line in ratio m:n
((mx₂-nx₁)/(m-n), (my₂-ny₁)/(m-n))Section formula (external)External division
((x₁+x₂)/2, (y₁+y₂)/2)Midpoint formulaCenter of line segment

Slope Formulas:

FormulaDescription
m = (y₂-y₁)/(x₂-x₁)Slope through two points
m = tan θSlope and angle of inclination
m₁ × m₂ = -1Perpendicular lines
m₁ = m₂Parallel lines

Equation of Straight Line:

FormEquationWhen to Use
Slope-intercepty = mx + cSlope m, y-intercept c known
Point-slopey - y₁ = m(x - x₁)Slope and one point known
Two-point(y-y₁)/(y₂-y₁) = (x-x₁)/(x₂-x₁)Two points known
Intercept formx/a + y/b = 1x-intercept a, y-intercept b
Normal formx cos α + y sin α = pPerpendicular distance from origin
General formAx + By + C = 0Standard form

Distance from Point to Line:

Distance from (x₁, y₁) to Ax + By + C = 0:

d = |Ax₁ + By₁ + C|/√(A² + B²)

Angle Between Two Lines:

  • tan θ = |(m₁ - m₂)/(1 + m₁m₂)|

Condition for Concurrency:

  • Three lines are concurrent if determinant = 0

💡 Quick Recall:

  • Slope = Rise/Run = Δy/Δx
  • Parallel lines never meet: m₁ = m₂
  • Perpendicular lines meet at 90°: m₁m₂ = -1

Chapter 11: Conic Sections Formulas Class 11

Complete Conic Sections Formulas (Circle, Parabola, Ellipse, Hyperbola)

Conic Sections carry significant weightage in JEE. These formulas are essential.

Circle Formulas:

EquationDescriptionParameters
(x-h)² + (y-k)² = r²Standard formCenter (h,k), radius r
x² + y² = r²Circle at originCenter (0,0), radius r
x² + y² + 2gx + 2fy + c = 0General formCenter (-g,-f), radius √(g²+f²-c)

Parabola Formulas:

Standard FormVertexFocusDirectrixAxisLatus Rectum
y² = 4ax(0,0)(a,0)x = -ax-axis4a
y² = -4ax(0,0)(-a,0)x = ax-axis4a
x² = 4ay(0,0)(0,a)y = -ay-axis4a
x² = -4ay(0,0)(0,-a)y = ay-axis4a

Ellipse Formulas:

Standard FormCenterFociMajor AxisEccentricity
x²/a² + y²/b² = 1 (a>b)(0,0)(±c,0)2ae = c/a = √(1-b²/a²)
x²/b² + y²/a² = 1 (a>b)(0,0)(0,±c)2ae = c/a = √(1-b²/a²)

Where: c² = a² - b²

Latus Rectum of Ellipse: 2b²/a

Hyperbola Formulas:

Standard FormCenterFociTransverse AxisEccentricity
x²/a² - y²/b² = 1(0,0)(±c,0)2ae = c/a = √(1+b²/a²)
y²/a² - x²/b² = 1(0,0)(0,±c)2ae = c/a = √(1+b²/a²)

Where: c² = a² + b²

Latus Rectum of Hyperbola: 2b²/a

Asymptotes: y = ±(b/a)x

Eccentricity Comparison:

  • Circle: e = 0
  • Ellipse: 0 < e < 1
  • Parabola: e = 1
  • Hyperbola: e > 1

JEE Tip: Remember "a² - b² for ellipse, a² + b² for hyperbola" when finding c.

Chapter 12: Introduction to 3D Geometry Formulas

Three Dimensional Geometry Formulas Class 11

Distance Formula in 3D:

Distance between A(x₁, y₁, z₁) and B(x₂, y₂, z₂):

d = √[(x₂-x₁)² + (y₂-y₁)² + (z₂-z₁)²]

Section Formula in 3D:

Point dividing line joining (x₁, y₁, z₁) and (x₂, y₂, z₂) in ratio m:n:

((mx₂+nx₁)/(m+n), (my₂+ny₁)/(m+n), (mz₂+nz₁)/(m+n))

Midpoint Formula:

  • Midpoint = ((x₁+x₂)/2, (y₁+y₂)/2, (z₁+z₂)/2)

Centroid of Triangle:

For vertices A(x₁,y₁,z₁), B(x₂,y₂,z₂), C(x₃,y₃,z₃):

G = ((x₁+x₂+x₃)/3, (y₁+y₂+y₃)/3, (z₁+z₂+z₃)/3)

Chapter 13: Limits and Derivatives Formulas Class 11

Important Calculus Formulas: Limits and Derivatives

Calculus is the foundation for Class 12 and engineering. Master these basics.

Standard Limits:

LimitValueApplication
lim(x→0) (sin x)/x1Trigonometric limits
lim(x→0) (1 - cos x)/x0Trigonometric limits
lim(x→0) (tan x)/x1Trigonometric limits
lim(x→0) (eˣ - 1)/x1Exponential limits
lim(x→0) (aˣ - 1)/xlog aExponential limits
lim(x→0) (log(1+x))/x1Logarithmic limits
lim(x→∞) (1 + 1/x)ˣeEuler's number
lim(x→0) (1 + x)^(1/x)eEuler's number

Derivative Formulas (First Principles):

  • f'(x) = lim(h→0) [f(x+h) - f(x)]/h

Standard Derivatives:

FunctionDerivativeFunctionDerivative
xⁿnxⁿ⁻¹c (constant)0
sin xcos xcos x-sin x
tan xsec²xcot x-cosec²x
sec xsec x tan xcosec x-cosec x cot x
aˣ log a
log x1/x√x1/(2√x)

Derivative Rules:

RuleFormula
Sum/Differenced/dx[f(x) ± g(x)] = f'(x) ± g'(x)
Product Ruled/dx[f(x)g(x)] = f'(x)g(x) + f(x)g'(x)
Quotient Ruled/dx[f(x)/g(x)] = [g(x)f'(x) - f(x)g'(x)]/[g(x)]²
Chain Ruled/dx[f(g(x))] = f'(g(x)) × g'(x)
Constant Multipled/dx[cf(x)] = c f'(x)

Memory Trick:

  • "Product Rule: First Der-Second + First-Second Der"
  • "Quotient Rule: Bottom Der-Top minus Top Der-Bottom, all over Bottom squared"

Chapter 14: Mathematical Reasoning

Mathematical Reasoning: Statements and Logical Operations

Types of Statements:

  • Simple Statement: Can be clearly identified as true or false
  • Compound Statement: Combination of two or more statements

Logical Connectives:

ConnectiveSymbolExample
AND (Conjunction)p ∧ q
OR (Disjunction)p ∨ q
NOT (Negation)~ or ¬~p
Implies (Conditional)→ or ⇒p → q
If and only if (Biconditional)↔ or ⇔p ↔ q

Truth Tables: Covered in detail in NCERT with standard results.

Contrapositive, Converse, Inverse:

  • Statement: p → q
  • Contrapositive: ~q → ~p (equivalent to original)
  • Converse: q → p
  • Inverse: ~p → ~q

Chapter 15: Statistics Formulas Class 11

Important Statistics Formulas for Class 11

Measures of Central Tendency:

MeasureFormula (Ungrouped)Formula (Grouped)
Mean (x̄)Σx/nΣfx/Σf
MedianMiddle value when arrangedL + [(n/2 - cf)/f] × h
ModeMost frequent valueL + [(f₁-f₀)/(2f₁-f₀-f₂)] × h

Measures of Dispersion:

MeasureFormula
RangeLargest value - Smallest value
Mean Deviation (MD)Σ|x - x̄|/n
Variance (σ²)Σ(x - x̄)²/n
Standard Deviation (σ)√[Σ(x - x̄)²/n]
Coefficient of Variation(σ/x̄) × 100

Alternative Formula for Variance:

  • σ² = (Σx²/n) - (x̄)²

Chapter 16: Probability Formulas Class 11

Basic Probability Formulas for Class 11 Maths

Fundamental Probability:

  • P(E) = (Number of favorable outcomes)/(Total number of outcomes)
  • 0 ≤ P(E) ≤ 1
  • P(E) + P(E') = 1 (Complementary events)

Addition Theorems:

RuleFormulaCondition
Mutually ExclusiveP(A ∪ B) = P(A) + P(B)A ∩ B = φ
General AdditionP(A ∪ B) = P(A) + P(B) - P(A ∩ B)Any events
Three EventsP(A∪B∪C) = P(A)+P(B)+P(C)-P(A∩B)-P(B∩C)-P(A∩C)+P(A∩B∩C)Any events

Conditional Probability:

  • P(A|B) = P(A ∩ B)/P(B), where P(B) ≠ 0

Multiplication Theorem:

  • P(A ∩ B) = P(A) × P(B|A) = P(B) × P(A|B)
  • For independent events: P(A ∩ B) = P(A) × P(B)

Independent Events:

  • Events A and B are independent if P(A ∩ B) = P(A) × P(B)

Bayes' Theorem:

  • P(E₁|A) = [P(E₁)P(A|E₁)]/[Σ P(Eᵢ)P(A|Eᵢ)]

How to Remember Class 11 Maths Formulas Quickly: Proven Tips

Effective Formula Memorization Strategies

1. Chapter-Wise Formula Cards

Create flashcards for each chapter with:

  • Formula on front
  • Application/example on back
  • Color-code by difficulty

2. Daily Revision Routine

  • Morning: Review 2-3 chapters (10 mins)
  • Night: Practice problems using formulas (20 mins)
  • Weekend: Complete chapter revision

3. Mnemonic Techniques

  • Trigonometry: "All Students Take Calculus" (All positive in 1st quadrant, Sin in 2nd, Tan in 3rd, Cos in 4th)
  • Conic Sections: "Circle = 0, Ellipse < 1, Parabola = 1, Hyperbola > 1" (eccentricity)

4. Formula Derivation Practice

Understanding derivation = better retention. Derive at least once:

  • Quadratic formula
  • Sum of GP
  • Distance formula
  • Binomial theorem

5. Practice with Variety

  • NCERT Examples → Exercise → Exemplar → Previous Years
  • Each application reinforces memory

6. Visual Learning

  • Draw diagrams for geometry chapters
  • Create mind maps linking related formulas
  • Use colored pens for better recall

7. Group Study Formula Quiz

  • Weekly quiz with friends
  • Teach formulas to others (best retention method)

8. Mobile Wallpaper Trick

Set your phone wallpaper to a formula sheet. You'll see it 50+ times daily!

Chapter-Wise Exam Weightage: CBSE Board & JEE

Which Chapters Are Most Important for Exams?

ChapterCBSE Marks
Trigonometric Functions12-15
Limits and Derivatives10-12
Permutations & Combinations8-10
Binomial Theorem6-8
Sequences and Series8-10
Conic Sections8-10
Straight Lines6-8
Complex Numbers6-8
Probability6-8
Statistics6-8
Sets4-6
3D Geometry4-6

Common Mistakes Students Make with Class 11 Maths Formulas

Common Maths Formula Mistakes Class 11 Students Should Avoid

Many students lose marks in CBSE board exams and JEE Main because they apply formulas incorrectly. Here are the most common Class 11 Maths formula mistakes and the correct methods to avoid them.

1. Trigonometry Formula Mistakes

Students often confuse trigonometric identities with normal algebraic addition.

Wrong Formula

sin(A+B) = sin A + sin B

Correct Formula

sin(A+B) = sin A cos B + cos A sin B

Why this mistake happens: Many students forget that trigonometric angle formulas are identities, not simple algebraic expansions.

Quick Revision Tip: Sine addition always contains both sin and cos, and two terms are always present.

2. Permutation vs Combination Confusion

This is one of the most common mistakes in Class 11 Maths.

Wrong Approach

Using permutation formulas for selection-based questions.

Correct Concept

  • Permutation: Arrangement matters
  • Combination: Selection matters
SituationFormula Type
Arranging students in a rowPermutation
Selecting students for a teamCombination

Quick Memory Trick: P = Position, C = Choose.

3. GP Sum Formula Errors

Students often use the same GP formula in every question without checking the value of the common ratio.

Incorrect Formula Usage

Sn = a(rn - 1) / (r - 1)

Correct Formula Selection

If r > 1:

Sn = a(rn - 1) / (r - 1)

If r < 1:

Sn = a(1 - rn) / (1 - r)

Important Tip: Always check whether r > 1 or r < 1 before applying the GP sum formula.

4. Complex Number Multiplication Mistakes

Students frequently forget that:

i2 = -1

Wrong Multiplication

(a + ib)(c + id) = ac + bd + i(ad + bc)

Correct Multiplication

(a + ib)(c + id) = (ac - bd) + i(ad + bc)

Why this happens: The negative sign generated by i2 = -1 is often ignored.

5. Limits and Indeterminate Forms

Common Mistake

Stopping immediately after getting:

0 / 0

Correct Method

  • Factorization
  • Rationalization
  • Standard limits
  • Trigonometric identities

Exam Tip: Whenever you get an indeterminate form, simplify first and substitute later.

6. Straight Lines and Slope Confusion

Wrong Understanding

Thinking perpendicular slopes are simply negative reciprocals without checking the condition.

Correct Formula

m1 × m2 = -1

Important Concepts

Line TypeCondition
Parallel Linesm1 = m2
Perpendicular Linesm1m2 = -1

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FAQs: Class 11 Maths Formulas

How many formulas are there in Class 11 Maths?

There are approximately 150-200 important formulas across all 16 chapters. However, focus on mastering 80-100 most frequently used formulas first. Trigonometry alone has 40+ formulas, followed by Calculus and Coordinate Geometry.

Which chapter has the most formulas in Class 11 Maths?

Trigonometric Functions (Chapter 3) has the maximum formulas, including basic ratios, identities, sum/difference formulas, double/triple angles, and product-to-sum conversions. Conic Sections and Limits/Derivatives also have extensive formula lists.

Are Class 11 Maths formulas enough for JEE preparation?

Class 11 formulas form the foundation (40% of JEE syllabus), but you'll need Class 12 formulas and advanced problem-solving for JEE. However, mastering Class 11 thoroughly is crucial as concepts build upon each other.

How to remember Class 11 Maths formulas without forgetting?

  • Practice daily (even 15 minutes)
  • Derive formulas once to understand logic
  • Use flashcards and mnemonics
  • Apply formulas in problems immediately
  • Revise frequently (spaced repetition)
  • Teach formulas to classmates

Do I need to memorize all Class 11 Maths formulas?

No. Focus on understanding and memorizing high-frequency formulas. Some complex formulas can be derived from basic ones during exams if you understand the concepts.

Can I download Class 11 Maths formulas as PDF?

Infinity Learn provide free downloadable PDFs including a complete formula book, one-page cheat sheet, chapter-wise PDFs, and handwritten notes. Links are available in the download section above.

What's the difference between NCERT and reference book formulas?

NCERT contains all essential CBSE formulas. Reference books may include additional shortcuts and variations, but NCERT formulas are sufficient for CBSE boards. For JEE, you might need a few extra formulas and techniques.