A-Level Maths · Pure Mathematics
Binomial Expansion
What is it
The binomial expansion gives a formula for expanding expressions like (a + b)ⁿ without multiplying it out term by term, using binomial coefficients (nCr) to find each term directly.
Why it matters
Beyond expanding brackets efficiently, the binomial expansion extends to fractional and negative powers, giving an approximation method that's genuinely used in physics and engineering to simplify complex expressions.
Exam tip
Write out the general term formula before substituting specific values — attempting to jump straight to numerical coefficients without the general term is where most binomial expansion errors occur.
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