I looked at the trig identities but I couldn't figure out what they wanted. Here they always say "prove that X+Y+Z can be written as A-B/C" or whatever OR they say "y=blahblah, find x within 0<x<360 degree/radians" so I couldn't figure out whether you need to rearrange them or find a numerical value, I went with rearranging but then realised I don't know what I'm supposed to be rearranging it to so won't know when I've finished?! Haha.
Then I got bored and did my intergration revision
Sorry, I tried!