1) 2/cos^2x+1/sin^2 = (2 sin^2x+cos^2x)/cos^2x*sin^2x= (sinx+1)/cos^2x*sin^2x
2)(sinx)'*(1+cosx)+sin(1+cosx)' = cosx+cos^2x-sin^2x=cosx-cos2x
3)2-3cos3x
4)3' - ((2tgx)' *tgx-2tgx*(tgx)')/tg^2x= (-2tgx/cos^2x-2tgx/cos^2x)/tg^2x=0
5)3'- 1/3(cosx)' +(cosx)' = 1/3sinx-sinx=2/3sinx