Fig. 2

Plot of singular periodic solution (20) for the solutions (a, c) \(\Re (f)\), (b, d) \(\Im (f)\), where \(f=f_{1,2}(x,t)\).
Plot of singular periodic solution (20) for the solutions (a, c) \(\Re (f)\), (b, d) \(\Im (f)\), where \(f=f_{1,2}(x,t)\).