second order ODE diff

Hello,

I have this second order ODE for damped oscillator. Easy way to solve it would be using ODE45 but I need to use MATLAB function 'diff' to obtain velocity and acceleration.

syms  x(t) sin(t) 
eq(t)=diff(x,t,t)+0.78*diff(x,t)+14*x==0.56*sin(t*147);
vel=diff(eq,t);
acc=diff(eq,t,t);

I've got to this point so far. But I can't work out what to do next or even if I'm on the right track.

Thanks

Answer 1

[Torsten]

syms x(t)
eqn=diff(x,t,2)+0.78*diff(x,t)+14*x==0.56*sin(t*147);
xsol(t)=dsolve(eqn);
vel(t)=diff(xsol,t)
acc(t)=diff(xsol,t,2)