Mental math and more identities

Well today we started our class with a quick mental math, followed by another one, and then yet another one Which gave us a total of 15 questions which didn't help to many of us in the marks department. After that happened we had members of the safe grad committee come in and try to get everyone to vote on the theme, with the choices being carnival, Miami, Paris, or 80's night club. Finally we came to doing more identities and are now to the find a point using two angles by either using addition or subtraction. The main way this works is by using one of the following identities:

With alpha representing one angle and beta the other angle. Here is the example question we did in class as well as where it would be on the unit circle.

Finnally at the end of the day we were told to do the homework we were previously assigned and to keep working on accelerated math because a mark is going in for it before parent- teacher interviews.