16S3: AM Trigo lesson 8 - Double angle formula by Gary Ang | Aug 22, 2016 | 16S3, Board-casts | 0 comments [vimeography id="630"] In this lesson, we started on the double angle formula. Submit a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Email * Website Save my name, email, and website in this browser for the next time I comment. Δ