a stands for alpha b stands for beta
a)cos(a+b)= b)2cos squared a - 1=
c)tan2a= d)sin1/2theta=
e) sin a =
1+ cos a
For a) - d) use the link I gave in your other thread.
For e) what are you looking for? This is
right? There are any number of equivalent forms that we might create from this. I'm not sure which one you would be looking for?
-Dan