Prove-without-using-Mathematical-Induction-that-cos-n-x-1-2-n-1-k-0-n-1-2-C-k-n-cos-n-2k-x-where-x-is-any-real-number-and-n-is-any-positive-odd-integer-

Question Number 169295 by thfchristopher last updated on 28/Apr/22

Prove without using Mathematical

Induction that :

\cos^{n} x = \frac{1}{2^{n - 1}} \underset{k = 0}{\sum^{(n - 1) / 2}} C_{k}^{n} \cos (n - 2 k) x

where x is any real number and n is any

positive odd integer .