b=.01
w=.9
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==5.2,
x'[0]==.44},{x},{t,0,70}]

plot11=Plot[Evaluate[x[t]/.First[solution]],{t,0,70},PlotRange->All]


b=.01
w=.95
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==9.9,
x'[0]==1.8},{x},{t,0,70}]

plot12=Plot[Evaluate[x[t]/.First[solution]],{t,0,70},PlotRange->All]


b=.01
w=1
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==0,
x'[0]==50},{x},{t,0,70}]

plot21=Plot[Evaluate[x[t]/.First[solution]],{t,0,70},PlotRange->All]


b=.01
w=1.05
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==-9.4,
x'[0]==2},{x},{t,0,70}]

plot22=Plot[Evaluate[x[t]/.First[solution]],{t,0,70},PlotRange->All]


b=.01
w=1.1
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==-4.7,
x'[0]==.5},{x},{t,0,70}]

plot31=Plot[Evaluate[x[t]/.First[solution]],{t,0,70},PlotRange->All]


b=.01
w=1
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==0,
x'[0]==0},{x},{t,0,200}]

plot32=Plot[Evaluate[x[t]/.First[solution]],{t,0,200},PlotRange->All]

b=.01
w=1
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==Cos[w t],
  x[0]==100,
x'[0]==0},{x},{t,0,200}]

plot41=Plot[Evaluate[x[t]/.First[solution]],{t,0,200},PlotRange->All]

b=.01
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==0,
  x[0]==100,
x'[0]==0},{x},{t,0,200}]

plot42=Plot[Evaluate[x[t]/.First[solution]],{t,0,200},PlotRange->All]

b=1
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==0,
  x[0]==0,
x'[0]==100},{x},{t,0,10}]

plot51=Plot[Evaluate[x[t]/.First[solution]],{t,0,10},PlotRange->All]

b=2
solution=NDSolve[{
x''[t]+2 b x'[t] + x[t]==0,
  x[0]==10,
x'[0]==-100},{x},{t,0,10}]

plot52=Plot[Evaluate[x[t]/.First[solution]],{t,0,10},PlotRange->All]

out=GraphicsGrid[{
{plot11,plot12},
{plot21,plot22},
{plot31,plot32},
{plot41,plot42},
{plot51,plot52}}]

