Which of the following functions of time represent (a) simple harmonic, (b) periodic but not simple harmonic, and (c) non-periodic motion? Give period for each case of periodic motion (ω is any positive constant):
- cos ωt + cos 3ωt + cos 5ωt
- `e ^(–ω^2 t^2)`
- `1 + ωt + ω^2t^2`