solution

Joe Riel — Sun, 11 Mar 2012 19:15:47 Z

Your computation of the transfer function is correct, however, that is only a partial answer. One way to compute it is to use ?DynamicSystems:

deq := diff(y(t),t,t)+1/4*diff(y(t),t)+y(t)=g(t):
sys := DynamicSystems:-TransferFunction(deq,g,y):
sys:-tf;

I suspect that you want to find the complete solution, using the definition of g and the initial conditions. That can be done with ?dsolve:

dreq := g(t) = piecewise(t<=5,0,4);
ini := {y(0)=0, D(y)(0)=0};
dsolve( eval({deq},dreq) union ini );

Thank You

allmon84 — Sun, 11 Mar 2012 20:13:12 Z

Thank You
You saved me :D