In[]:=
xsol[t_]={x[t],x'[t]}/.NDSolvex''[t]+Sin[x[t]]0,x[0]
-π
4
,x'[0]-1.4,x,{t,0,7.96}[[1]];​​post[t_]={Sin[xsol[t][[1]]],-Cos[xsol[t][[1]]]};​​frames=Table[GraphicsGrid[{{Show[ListPlot[{xsol[t1]},PlotStylePointSize[0.04],PlotRange{{-2,2},{-2,2}},AspectRatio1,AxesLabel{"
x
1
​(t)","
x
2
​(t)"}],ParametricPlot[xsol[t],{t,0,7.96},PlotRange{{-2,2},{-2,2}},AspectRatio1]],Show[ListPlot[{post[t1]},PlotStylePointSize[0.04],PlotRange{{-2,2},{-2,2}},AspectRatio1],Graphics[Line[{{0,0},post[t1]}]]]}}],{t1,0,7.96,0.25}];​​ListAnimate[​​frames,SaveDefinitionsTrue]
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