PreCalculus - Trigonometry: Trig Identities (24 of 57) Double Angle Formula Proved: Cosine

preview_player
Показать описание

In this video I will prove the double angle formula cos2A=cos^2(A)-sin^2(A).
Рекомендации по теме
Комментарии
Автор

what is the reason that we playing Tig identities? how to use in real world application?
thank you sir

andrewskyworker
Автор

74 sec saved me from rotting
this must be magic

TonyKaku-gn