Which basic properties are needed for a system to oscillate?

The displacement of a particle is given by the relation $x = 4(\cos \pi t + \sin \pi t)$. The amplitude of the particle is

$A$ particle moves in $S.H.M.$ such that its acceleration is $a = -px$,where '$x$' is the displacement of the particle from the equilibrium position and '$p$' is a constant. The period of oscillation is

$A$ simple harmonic motion is represented by $y = 5(\sin 3\pi t + \sqrt{3} \cos 3\pi t) \ cm$. The amplitude and time period of the motion are:

Write the difference between periodic motion and simple harmonic motion.

The graphs in the figure show that a quantity $y$ varies with displacement $d$ in a system undergoing simple harmonic motion. Which graph best represents the relationship obtained when $y$ is the time?