Binomial Theorem

The Binomial Theorem $(a+b)^n = \sum_{k=0}^{n} {^nC_k}\,a^{n-k}b^k$ turns Pascal's triangle into a one-line expansion machine for any positive-integral power. Its special cases $(1 \pm x)^n$ yield the coefficient identities and power fast numerical computations, divisibility results and term-hunting — the staple JEE questions from this chapter.