In[]:=
dosc=20.0+(1.0*((Exp[-(0.02*t)])*((4.0*Cos[0.3*(t-0.0)])+(4.0*Sin[0.3*(t-0.0)]))));
In[]:=
gR[t_,r_]:=t*Cos[r]-(dosc)*Sin[r];hR[t_,r_]:=t*Sin[r]+(dosc)*Cos[r];Manipulate[ParametricPlot[{gR[t,r],hR[t,r]},{t,0,75},PlotRange->{{-10,100},{-100,50}}],{r,0,-1.5}]
Out[]=
