Basic Mathematics by Serge Lang - 11.5 Addition Formula (Basic Mathematics)

Let's try to calculate what the sine and cosine of the sum of angles would be. Using this formula, we can also see how to calculate the sine and cosine of non-standard angles like pi/12. Importantly, we get to use the trigonometric identities to make our job pretty easy. Support Real Physics by buying the book through this Amazon affiliate link: https://amzn.to/2I5yIHr Here's my Patreon account if you want to give me money: https://www.patreon.com/realphysics Other ways to support Real Physics: https://youtu.be/44nldGgJCiw Playlist: https://www.youtube.com/playlist?list=PLMcpDl1Pr-viA25VUkHNmcUkWx9usPgyb Thank you!