omg I hate these things...

1. sin^4A + 2cos^2A - cos^4A = 1

2. cos3A = -3cosA+4cos^3A

3. cos^4A = 1/8(3 + 4cos2A + cos4A)

4. (1 - cosA)/sinA = tan(A/2)

5. sin2A = (2tanA)/1 + tan^2A

Well, these are all of them so far, because I haven't looked at them all yet. Trust me I tried to do these by myself, and succeded in some not on here, but I'm not an identities person.