Задача 28670 Все на картинке...
Условие
Все решения
=3cos^2(x-2sqrt(y))*(-sin(x-2sqrt(y))*(x-2sqrt(y))`_(x)=
=3cos^2(x-2sqrt(y))*(-sin(x-2sqrt(y))*1=
=-3sin(x-2sqrt(y))*cos^2(x-2sqrt(y))
z``_(xx)=(-3sin(x-2sqrt(y)))`_(x)*cos^2(x-2sqrt(y))+
+(-3sin(x-2sqrt(y)))*(cos^2(x-2sqrt(y)))`_(x)=
=-3cos(x-2sqrt(y))*cos^2(x-2sqrt(y))+
+(-3sin((x-2sqrt(y)))*(2cos(x-2sqrt(y)))*(cos(x-2sqrt(y)))`_(x)=
=-3cos^3(x-2sqrt(y))+6sin^2(x-2sqrt(y))*cos(x-2sqrt(y))
z`_(y)=3cos^2(x-2sqrt(y))*(cos(x-2sqrt(y))`_(y)=
=3cos^2(x-2sqrt(y))*(-sin(x-2sqrt(y))*(x-2sqrt(y))`_(y)=
=3cos^2(x-2sqrt(y))*(-sin(x-2sqrt(y))*(-1/sqrt(y))=
=(3/sqrt(y))*sin(x-2sqrt(y))*cos^2(x-2sqrt(y))
z``_(yy)=((3/sqrt(y))*sin(x-2sqrt(y))*cos^2(x-2sqrt(y)))`_(y) и так далее
считать производную произведения трех множителей.