Let a = (-1)" - sin{ 27 }; Oliminf a = -1 and lim sup a,, = 1 liminf a = 0 and lim sup a,, = 1 liminf a,,= -1 and lim sup a, = 0 liminf a,, = 1 and lim sup a,, = 0 n=1,2,..... Then,