[" Example "2." Which of the following functions of time "],[" represent (a) periodic and (b) non-periodic motion? Give the "],[" period for each case of periodic motion.[ o is any positive "],[" constant]."],[[" (i) "sin omega t+cos omega t," (ii) "sin omega t+cos20t+sin40t],[" (iii) "e^(-omega t)," (iv) "log(omega t)]]