Prove that \[ \sum_{k=1}^{n-1}{ }^{n} C_{k}[\cos k x \cdot \cos (n+k) x+\sin (n-k) x \cdot \sin ...
Channel:
Subscribers:
453,000
Published on ● Video Link: https://www.youtube.com/watch?v=fYnlvtDhru4
0Prove that
\[
\sum_{k=1}^{n-1}{ }^{n} C_{k}[\cos k x \cdot \cos (n+k) x+\sin (n-k) x \cdot \sin (2 n-k) x]=
\]
\( \left(2^{n}-2\right) \cos n x \).
ЁЯУ▓PW App Link - https://bit.ly/YTAI_PWAP
ЁЯМРPW Website - https://www.pw.live