Тригонометрия. Упростите. Cpoчно!

1) (sin^2x - cos^2x)^2 + sin^2*2x

2)((1/1-tgx) - (1/1+tgx))*(cos^2*x)

3) (tg^3*x-tg^3*y)/((1+tgxtgy)(tg^2*x+tgxtgy+tg^2*y))