Maths · Class 11 · Binomial Theorem and its Simple Applications

Binomial Theorem for JEE

Everything you need for this topic on one page: the ideas, the formulas, the traps, and free lectures that explain it well.

Last updated: 26 October 2026

Direct answer

Expansion of (a + b)ⁿ, general and middle terms, coefficient of a power, sum of coefficients and simple applications.

Expansion of (a + b)ⁿ, general and middle terms, coefficient of a power, sum of coefficients and simple applications.

Key ideas

Binomial Theorem: what you must understand

  • General term Tᵣ₊₁ = ⁿCᵣ aⁿ⁻ʳ bʳ
  • Middle term: one if n even, two if n odd
  • Sum of coefficients: put x = 1
  • Greatest coefficient is the middle binomial coefficient
Formula sheet

Must-know formulas for Binomial Theorem

  • Σ ⁿCᵣ = 2ⁿ
  • Sum of even-index coefficients = 2ⁿ⁻¹
  • Term independent of x: set power of x to 0
  • ⁿCᵣ + ⁿCᵣ₋₁ = ⁿ⁺¹Cᵣ
Print

One-page formula sheet

Printable Binomial Theorem formula sheet: formulas, key ideas and traps on one page. Save it as a PDF for offline revision.

Avoid

Common mistakes students make

  • Indexing Tᵣ instead of Tᵣ₊₁
  • Sign errors with (a − b)ⁿ
  • Forgetting negative powers of x in the general term
For the exam

How this topic is asked in JEE

Appears frequently. One question per shift is typical, often about a specific coefficient.

Prerequisites: Permutations and Combinations.

NCERT map

Where Binomial Theorem is in NCERT

Chapter names follow the current rationalised NCERT textbooks. Read these sections before solving PYQs.

ClassBookChapterSections JEE asks from
Class 11MathematicsBinomial TheoremBinomial Theorem for Positive Integral Indices; General and Middle Terms; Pascal's Triangle
JEE Advanced level

A JEE Advanced-level example on Binomial Theorem

Question. Find the coefficient of x¹⁰ in the expansion of (1 + x + x²)¹⁰.

Show solution
  1. Write (1 + x + x²)¹⁰ as [(1 + x) + x²]¹⁰ and expand using binomial theorem: Σ ¹⁰Cᵣ × (1+x)¹⁰⁻ʳ × x²ʳ for r = 0 to 10
  2. For x¹⁰, we need power k from (1+x)¹⁰⁻ʳ such that k + 2r = 10, so k = 10 − 2r
  3. Valid values: r = 0, 1, 2, 3, 4, 5 (since k must be between 0 and 10−r)
  4. Coefficient = Σ ¹⁰Cᵣ × ⁽¹⁰⁻ʳ⁾C₍₁₀₋₂ᵣ₎ for r = 0 to 5
  5. Calculate: ¹⁰C₀×¹⁰C₁₀ + ¹⁰C₁×⁹C₈ + ¹⁰C₂×⁸C₆ + ¹⁰C₃×⁷C₄ + ¹⁰C₄×⁶C₂ + ¹⁰C₅×⁵C₀ = 1 + 90 + 1260 + 4200 + 3150 + 252 = 8953

Answer: 8953

This example was solved twice independently and both solutions agree.

Free lectures

Best free lectures for Binomial Theorem

Full-chapter free lectures picked from YouTube search results by views, from established JEE channels (mostly in Hinglish). Use the subtopic list to jump straight to the part you need (timestamps come from each video's own chapter list). Watch one, then solve PYQs the same day.

Practise

Where to practise for free

FAQs

Frequently asked questions

Is Binomial Theorem important for JEE Main 2027?

Appears frequently. It is part of the official 'Binomial Theorem and its Simple Applications' unit in the JEE Main 2027 syllabus.

What are the most important formulas in Binomial Theorem?

Σ ⁿCᵣ = 2ⁿ; Sum of even-index coefficients = 2ⁿ⁻¹; Term independent of x: set power of x to 0.

How should I study Binomial Theorem for JEE?

Understand the key ideas from NCERT or one full lecture, learn the formula sheet, then solve 25–30 past JEE questions on the topic. One question per shift is typical, often about a specific coefficient.

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