O Level
O-Level Additional Mathematics: Binomial Theorem: Coefficient Tricks
•By Intuitional Team•1 min read
O-Level Additional Mathematics — Binomial Theorem: Coefficient Tricks: quick notes, common traps, and an exam-style example.
Binomial expansion
(1 + x)ⁿ = 1 + nx + n(n–1)x²/2! + … valid for |x| < 1 (if n not integer). For positive integers, expansion terminates.
Term finding
General term: Tᵣ₊₁ = C(n,r)aⁿ⁻ʳbʳ. Useful for coefficient extraction.
Exam habits
- State range of validity for expansions.
- Underline the requested coefficient clearly.
- Beware negative/fractional indices: series is infinite.
Tags
O-LevelAdditional MathematicsBinomial Theorem