Let be a positive integer greater than 1

MATHEMATICS · Multi-part · CBSE · Mathematics · Binomial Theorem · Binomial Theorem

Problem

Let nn be a positive integer greater than 1. Consider the binomial expansion of (1+x)n(1+x)^n. (i) Prove that the sum of the coefficients of the terms containing even powers of xx equals the sum of the coefficients of the terms containing odd powers of xx. (ii) Deduce that each of these sums is 2n−12^{n-1}. (iii) Using the result of part (ii), calculate the common value of these two sums when n=7n=7. No credit will be given for brute-force expansion.

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