if ics are v(0)=v'(0)=0 ...nix...

If I change to v''(t)+v'(t)+v(t)=sin(At) how do I get A a value to plot this function?

What I did wrong? restart; deq := diff(v(t),[t$2]) + diff(v(t),t) +v(t) = 0; dsolve(deq,v(t)); ics11:= v(0)=1,(D(v))(0)=0:ics12 := v(0)=0,(D(v))(0) = 0:ics13 := v(0) = -1, (D(v))(0) = 0: ics21 := v(0) = 0, (D(v))(0) = 1:ics22 := v(0) = 0, (D(v))(0) = 0:ics23 := v(0) = 0, (D(v))(0) = -1: cas11:=dsolve({deq, ics11}); cas12:=dsolve({deq, ics12}); cas13:=dsolve({deq, ics13}); cas21:=dsolve({deq, ics21}); cas22:=dsolve({deq, ics22}); cas23:=dsolve({deq, ics23}); with(DEtools): DEplot(deq,t=0..10,cas12,color=blue, stepsize=1,linecolour=red,arrows=MEDIUM)???????

My equation is v''(t)+v'(t)+v=0, and my initial conditions V(0)=a, V'(0)=0 How do I do it with Maple? Thanks ...nix...

Could this be the right answer?? Question: GENERAL SOLUTION FOR= v''(t)+v'(t)+v=0, deq:=diff(y(x),x,x)=x^2+x+1; dsolve(deq); I don't understand the drawing command. Could you help me to plot it? ...nix...

Sorry I have already solved. Thanks. ...nix...