CBSE Class 11 Maths (2026) has 14 chapters in 5 units, and its 80-mark paper leans on two blocks: Algebra (25 marks) and Sets & Functions (23 marks — including Trigonometry, the single biggest formula set in school maths). This page lists every chapter's key formulas — and Class 11 formulas do double duty: they're also the foundation layer for JEE and for Class 12 calculus.
- Unit weightage 2026
- 1. Sets · 2. Relations & Functions · 3. Trigonometric Functions
- 4. Complex Numbers · 5. Linear Inequalities · 6. Permutations & Combinations · 7. Binomial Theorem · 8. Sequences & Series
- 9. Straight Lines · 10. Conic Sections · 11. 3D Geometry (Intro)
- 12. Limits & Derivatives · 13. Statistics · 14. Probability
- Memory tricks · FAQs
Where the 80 marks live
| Unit (chapters) | Marks |
|---|---|
| Algebra (Ch 4–8) | 25 |
| Sets & Functions (Ch 1–3) | 23 |
| Coordinate Geometry (Ch 9–11) | 12 |
| Statistics & Probability (Ch 13–14) | 12 |
| Calculus (Ch 12) | 8 |
Theory 80 + internal 20. Note the reversal from Class 12: here Algebra and Trigonometry rule; Calculus is only 8 marks — but it becomes 35 next year, so Ch 12 is an investment, not a footnote.
Ch 1 — Sets 23-mark unit
| Formula | Used for |
|---|---|
| n(A∪B) = n(A) + n(B) − n(A∩B) | Two-set counting — the chapter's standard word problem |
| n(A∪B∪C) = Σn(A) − Σn(A∩B) + n(A∩B∩C) | Three-set inclusion–exclusion |
| Number of subsets of an n-element set = 2n | Power set size; proper subsets = 2n − 1 |
| (A∪B)′ = A′∩B′; (A∩B)′ = A′∪B′ | De Morgan's laws |
Ch 2 — Relations & Functions 23-mark unit
| Formula | Used for |
|---|---|
| n(A × B) = n(A) · n(B) | Size of the Cartesian product |
| Number of relations from A to B = 2pq | Where p = n(A), q = n(B) — a repeated 1-marker |
| Domain, range, and (f ± g), (fg), (f/g) rules | Algebra of real functions; f/g needs g(x) ≠ 0 |
Ch 3 — Trigonometric Functions 23-mark unit
| Formula | Used for |
|---|---|
| π radian = 180°; l = rθ | Degree–radian conversion; arc length |
| sin²x + cos²x = 1; 1 + tan²x = sec²x; 1 + cot²x = cosec²x | The three Pythagorean identities |
| sin(x ± y) = sin x cos y ± cos x sin y | Compound angles — the parent formulas of the whole chapter |
| cos(x ± y) = cos x cos y ∓ sin x sin y | |
| tan(x ± y) = (tan x ± tan y)/(1 ∓ tan x tan y) | |
| sin 2x = 2 sin x cos x = 2 tan x/(1 + tan²x) | Double angle — sine |
| cos 2x = cos²x − sin²x = 2cos²x − 1 = 1 − 2sin²x | Double angle — pick the form matching what's given |
| sin 3x = 3 sin x − 4 sin³x; cos 3x = 4 cos³x − 3 cos x | Triple angle |
| 2 sin x cos y = sin(x+y) + sin(x−y) | Product → sum (and its three siblings) |
| sin C + sin D = 2 sin((C+D)/2) cos((C−D)/2) | Sum → product (and its three siblings) — proving-identities workhorse |
Ch 4 — Complex Numbers & Quadratic Equations 25-mark unit
| Formula | Used for |
|---|---|
| i² = −1; i4k = 1 | Powers of i cycle every 4 |
| |z| = √(a² + b²) for z = a + ib | Modulus |
| z · z = |z|² | Product with the conjugate — rationalising divisions |
| 1/z = z/|z|² | Multiplicative inverse |
| x = (−b ± √(b² − 4ac))/2a | Quadratic roots; D < 0 gives the complex pair |
Ch 5 — Linear Inequalities 25-mark unit
| Rule | Used for |
|---|---|
| Multiplying/dividing by a negative number FLIPS the inequality sign | The chapter's one non-negotiable rule — and its favourite trap |
Ch 6 — Permutations & Combinations 25-mark unit
| Formula | Used for |
|---|---|
| n! = n(n−1)(n−2)…1; 0! = 1 | Factorial basics |
| nPr = n!/(n−r)! | Arrangements (order matters) |
| nCr = n!/(r!(n−r)!) | Selections (order doesn't matter) |
| nCr = nCn−r | Symmetry — compute the smaller side |
| nCr + nCr−1 = n+1Cr | Pascal's rule |
| Permutations with repetition: n!/(p! q! …) | Arranging letters of words like MISSISSIPPI |
Ch 7 — Binomial Theorem 25-mark unit
| Formula | Used for |
|---|---|
| (a + b)n = Σ nCr an−r br, r = 0 to n | The expansion — n + 1 terms, coefficients from Pascal's triangle |
| Σ nCr = 2n (put a = b = 1) | Sum of binomial coefficients |
Note: general term and middle term are not in the current rationalized syllabus — the chapter is expansion and simple applications only.
Ch 8 — Sequences & Series 25-mark unit
| Formula | Used for |
|---|---|
| A.P. recap: an = a + (n−1)d; Sn = (n/2)[2a + (n−1)d] | Carried from Class 10 — assumed known |
| G.P.: an = arn−1 | nth term of a geometric progression |
| Sn = a(rn − 1)/(r − 1), r ≠ 1 | Sum of n terms of a G.P. |
| S∞ = a/(1 − r), |r| < 1 | Infinite G.P. — a favourite 2-marker |
| A.M. = (a + b)/2; G.M. = √(ab); A.M. ≥ G.M. | Means and the inequality between them |
Ch 9 — Straight Lines 12-mark unit
| Formula | Used for |
|---|---|
| m = (y2 − y1)/(x2 − x1) | Slope; parallel ⇔ m1 = m2; perpendicular ⇔ m1m2 = −1 |
| tan θ = |(m2 − m1)/(1 + m1m2)| | Angle between two lines |
| y − y1 = m(x − x1); y = mx + c; x/a + y/b = 1 | Point-slope, slope-intercept and intercept forms |
| d = |Ax1 + By1 + C|/√(A² + B²) | Distance of a point from a line — the unit's flagship numerical |
| d = |C1 − C2|/√(A² + B²) | Distance between parallel lines |
Ch 10 — Conic Sections 12-mark unit
| Formula | Used for |
|---|---|
| Circle: (x − h)² + (y − k)² = r² | Centre (h, k), radius r |
| Parabola: y² = 4ax | Focus (a, 0), directrix x = −a, latus rectum 4a |
| Ellipse: x²/a² + y²/b² = 1 (a > b) | c² = a² − b²; e = c/a < 1; latus rectum 2b²/a |
| Hyperbola: x²/a² − y²/b² = 1 | c² = a² + b²; e = c/a > 1; latus rectum 2b²/a |
Ch 11 — Introduction to 3D Geometry 12-mark unit
| Formula | Used for |
|---|---|
| d = √((x2−x1)² + (y2−y1)² + (z2−z1)²) | Distance between two points in space — effectively the whole chapter now (section formula is out of the rationalized syllabus) |
Ch 12 — Limits & Derivatives 8 marks (35 next year!)
| Formula | Used for |
|---|---|
| limx→a (xn − an)/(x − a) = n·an−1 | The algebraic standard limit |
| limx→0 (sin x)/x = 1 | The trigonometric standard limit — combines with everything |
| f′(x) = limh→0 [f(x+h) − f(x)]/h | First-principles derivative — a guaranteed question |
| (uv)′ = u′v + uv′; (u/v)′ = (u′v − uv′)/v² | Product and quotient rules |
| d/dx: xn → nxn−1; sin x → cos x; cos x → −sin x | Standard derivatives — the seed table for Class 12 |
Ch 13 — Statistics 12-mark unit
| Formula | Used for |
|---|---|
| Mean deviation = Σ|xi − x|/n | About the mean (or median — replace x with M) |
| σ² = Σ(xi − x)²/n | Variance; σ = its square root |
| σ² = (Σxi²/n) − (x)² | Shortcut form — faster for raw data |
Ch 14 — Probability 12-mark unit
| Formula | Used for |
|---|---|
| P(E) = n(E)/n(S) | Classical probability |
| P(A∪B) = P(A) + P(B) − P(A∩B) | Addition theorem; mutually exclusive ⇒ P(A∩B) = 0 |
| P(A′) = 1 − P(A) | Complement — "at least one" problems: 1 − P(none) |
Memory tricks for the heaviest sets
Trigonometry is 4 parents + machinery. The compound-angle formulas sin(x±y), cos(x±y) generate everything else: put y = x for double angles, combine for triple angles, add/subtract pairs for product↔sum conversions. Memorise 4, derive 15.
cos 2x has three costumes: cos²−sin², 2cos²−1, 1−2sin². Pick by what the question gives you — the third form is also how Class 12's integration handles sin²x and cos²x, so this one pays twice.
P vs C in one question: does swapping two chosen items create a new outcome? Yes → arrangement → nPr. No → selection → nCr.
Conic identifier: both squares, same sign, equal coefficients → circle; one square only → parabola; both squares, same sign, unequal → ellipse; opposite signs → hyperbola. And the c² memory hook: ellipse subtracts (a² − b²), hyperbola adds (a² + b²).
"At least one" = 1 − P(none). This single complement trick solves the majority of Class 11 probability word problems in two lines.
The complete handwritten Class 11 Maths formula sheet
This page gives you the core list. The handwritten sheet is the wall-chart version:
- Full Class 11 syllabus — all 14 chapters, compact and exam-focused
- Colour-coded formula boxes with the trig families grouped visually
- Real handwritten notes by toppers — IITians, NITians and district toppers
- Instant PDF or printed book (COD available, all-India delivery)
- Available in English and Hindi medium — also as a combined Class 11 + 12 set
FAQs
How many formulas are there in Class 11 Maths?
Roughly 100–120 core formulas across 14 chapters, with Trigonometric Functions alone contributing around 25 — the single biggest formula set in school maths.
Which unit has the highest weightage in Class 11 Maths 2026?
Algebra (Ch 4–8) at 25 marks, followed closely by Sets & Functions (Ch 1–3, including Trigonometry) at 23 — together they're 48 of the 80 theory marks.
Is Mathematical Induction in the Class 11 syllabus?
No. Principle of Mathematical Induction and Mathematical Reasoning are both removed under the rationalized syllabus, and Binomial Theorem no longer includes general and middle terms.
How do I memorise all the trigonometry formulas?
Learn the four compound-angle parents — sin(x±y) and cos(x±y) — and derive the rest: double angles by putting y = x, product-sum by adding pairs. Four memorised formulas generate about fifteen.
Is Class 11 Maths harder than Class 12?
Most students find Class 11 broader (14 varied chapters, heavy trigonometry and algebra) while Class 12 is deeper but more concentrated — Calculus alone is 35 of its 80 marks, and it's built on Class 11's Chapter 12.
Is there a Class 11 Maths formula sheet in Hindi?
Yes — the handwritten formula sheet linked above is available in both English and Hindi medium versions.
Which Class 11 formulas are most important for JEE?
Trigonometric identities, quadratic equations, permutations–combinations, A.M. ≥ G.M., and the standard limits — these five sets appear across JEE papers every year.
Do Class 11 formulas come in the Class 12 board exam?
Not directly as questions, but constantly as tools — Class 12 integration and differentiation lean on Class 11 trig identities and standard derivatives at every step.