Which of the following functions of time represent (a) periodic and (b) non-periodic motion? Give the period for each case of periodic motion [`omega` is any positive constant].
(i) `sinomegat+cosomegat`
(ii) `sinomegat+cos2omegat+sin4omegat`
(iii) `e^(-omegat)`
(iv) `log(omegat)`

Explanation

The function `e^(-omega t)` is not periodic, it decreases monotonically with increasing time and tends to zero at `t to oo` and thus, never repeats its value. So it is a non-periodic function.