Matlab：edit，then add the the following values in a m.file

` %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%`

function dx=myfun(t,x) dx(1)=-6*x(2)*x(2)-9; dx(2)=-3*x(1)*x(2)-2*x(3)-Yvv-Yuu; dx(3)=x(1)*x(2)+x(3)+8; Yvv=0.5*p*L*T*(0.048265-6.293*(1-c)*T/B); Yuu=0.5*p*L*L*L*T*(0.0045-0.445*(1-c)*T/B); dx=dx(:); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Finally,， Matlab ：

` clear all clc syms Yvv Yuu p L T c T B x0=[1,1,1]; t0=0:0.1:2; [t,x]=ode45('myfun',[0,10],x0); %ode45会自动调整步长`

plot(t,x) legend('u','v','Y')

## Best Answer