Sketch a graph of $x(t)=4.0~\mathrm{cm} + (3.0~\mathrm{cm}) \cos\left( (628~\frac{\mathrm{rad}}{\mathrm{sec}}) t - (\frac{2\pi}{3}~\mathrm{rad})\right)$. Label axes and show at least 2 complete cycles. What are the amplitude $A$, period $T$ and frequency $f$ (in Hz) of this motion?