1. (sin2x + cos2x) ^2=1

solutions are in the interval [0, 2pi)

using double angle formulas find sin2u , cos2u, and tan2u in:

2. cot u = -6, 3pi/2< u < 2pi

rewrite the expression in terms of the first power of cos:

3. sin^4x*cos^2x

i get stuck in between theses problems, its usually the factoring...