Binomial Expansions: Complete Theory and Formulas 1
Binomial Expansions: Complete Theory and Formulas 1. Introduction to Binomial Coefficients Binomial coefficients are fundamental mathematical concepts used in algebra and probability. They are represented in two ways: • ⁿCᵣ • (n r) or (n choose r) 2. Methods to Calculate Binomial Coefficients 2.1 Pascal's Triangle Method Pascal's Triangle provides a visual way to find binomial coefficients: 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1 1 5 10 10 5 1 2.2 Formula Method (n r) = n! / (r!(n-r)!) or (n r) = n × (n-1) × (n-2) × ... × (n-r+1) / (r × (r-1) × (r-2) × ... × 1) 3. The Binomial Theorem For any positive integer n, the expansion of (1 + x)ⁿ is given by: (1 + x)ⁿ = (n 0) + (n 1)x + (n 2)x² + ... + (n n)xⁿ 4. General Form of Binomial Expansion For any constants a and b, and positive integer n: (a + b)ⁿ = (n 0)aⁿ + (n 1)aⁿ⁻¹b + (n 2)aⁿ⁻²b² + ... + (n n)bⁿ