(xtg^2(x^2))'=tg^2(x^2)+2x^2*2tg(x^2)*1/cos^2(x^2)
(x^2cos(x-1)/(x+1))'=2xcos(x-1)/(x+1)-x^2sin(x-1)/(x+1)*((x+1)-(x-1))/(x+1)^2=
=2xcos(x-1)/(x+1)-2x^2sin(x-1)/(x+1)*1/(x+1)^2
(xtg^2(x^2))'=tg^2(x^2)+2x^2*2tg(x^2)*1/cos^2(x^2)
(x^2cos(x-1)/(x+1))'=2xcos(x-1)/(x+1)-x^2sin(x-1)/(x+1)*((x+1)-(x-1))/(x+1)^2=
=2xcos(x-1)/(x+1)-2x^2sin(x-1)/(x+1)*1/(x+1)^2