1.
Out of the following functions representing motion of a particle which represents SHM: I. y=sinωtcosωty = \sin\omega t - \cos\omega t, II. y=sin3ωty = \sin^3\omega t, III. y=5cos(3π/43ωt)y = 5\cos(3\pi/4 - 3\omega t), IV. y=1+ωt+ω2t2y = 1 + \omega t + \omega^2 t^2