diff(x,t,2) = f1(diff(x,t),diff(y,t)); diff(y,t,2) = f2(diff(x,t),diff(y,t)); initial conditions at t=0: x:Xo;? y:Yo;? diff(x,t):Vxo;? diff(y,t): Vyo; Please, What is the most expedient method for solving the above system of differential equations using Maxima?