Prove: Cos4A= 1-8sin^2 A +8sin^4 A

Prove: Cos4A= 1-8sin^2 A +8sin^4 A Trigonometry: Multiple Angles FOLLOW US: Facebook: www.facebook.com/mathswitharjun Twitter: www.twitter.com/twitajr ... https://www.youtube.com/watch?v=lIWM9lxOoag