Почему не компилирует?
waveequation = d^2/dt^2 u[x, t] == d^2/dx^2 u[x, t]
boundarycondition = {u[0, t] == 0, u[Pi, t] == 0};
initialcondition = {u[x, 0] == x^2 (Pi - x), (u^(0, 1))[x, 0] == 0};
dslo = Dsolve[{waveequation, boundarycondition, initialcondition},
u, {x, t}] /. {K[1] -> m}
asol[x_, t_] = u[x, t] /. dsol[[1]] /. {\[Infinity] -> 4} // Activate