Which of the following functions of time represent (a) simple harmonic, (b) periodic but not simple harmonic, and (c) non periodic motion (omega is any positive constant):
.(i) `sinomegat-cosomegat`
(ii)`sin^(3)omegat`
(iii) `3cos((x)/(4)-2omegat)`
(iv)`cosomegat+cos3omegat+cos5omegat`
(v)`exp(-omega^(2)t^(2))`
(vi) `1+omegat+omega^(2)t^(2)`

Explanation

`e^(-omega^(2)t^(2))` is not periodic as t increases the function `e^(-omega^(2)t^(2))` decreases and tends to zero as `t to oo`