Variable t=[0:0.1:5],x=0,y=0,x'=0,y'=0;
Plot t[x],x,y[y2];
ODEFunction y''=y''+(34/3+4*cos(y))*x''+(11/3+2*cos(y))*y''+2*(2+x'+y')*y'*sin(y)+30*sin(x)+10*sin(x+y)-sin(t);
            x''=x''+(11/3+2*cos(y))*x''+11/3*y''+2*y'^2*sin(y)+10*sin(x+y)-sin(t);