> 4*cos(x^2)*x^2*z(x)+x*sin(x^2)*diff(z(x),x)-sin(x^2)*z(x) = 0;

> solve(%,diff(z(x),x));

> int(-1/z,z)=int(4*cot(x^2)*x-1/x,x);

> solve(%,z);

> int(%,x);

> %*sin(x^2);

> y2:=unapply(%,x);

> x*diff(y2(x),x,x)-diff(y2(x),x)+4*x^3*y2(x)=0;

> simplify(%);