Use the addition formulas to find the exact value of the given expression
1) Cos 11(pi)/12
2) Sin23 cos37 + cos23 sin37
sin(u +/- v) = (sin u cos v +\- cos u sin v)
cos(u +/- v) = (cos u cos v -\+ sin u sin v)
tan(u +/- v) = (tan u +\- tan v) / (1 -\+ tan u tan v)
My teacher gave this worksheet and gave the answers and is grading on the work and process... unfortunately i was sick the day we learned how to do these. Any help AND explanation would be greatly apreciated!