(11)GiveoneexampleofCausal,AnticausalandBothesidedsignal. (12)Whatisanenergysignal?Giveexample. (13)Considerx 1 [n]isperiodicwithperiod=4andx 2 [n]isperiodicwithperiod=6. Letx[n]=x 1 [n]+x 2 [n].Whatwillbetheperiodofx[n]? (14)Whatispowersignal?Giveexample. (15)Whatissymmetricsignal?