Amplitude(A), Period(T) and Frequency(n) of S.H.M.

Having obtained the general displacement expression $x = A\sin(\omega t+\phi)$ in section 5.5, we are now in a position to formally define and derive expressions for the three quantities that, between them, completely characterise any particular S.H.M.: its amplitude (how far it swings), its period (how long one swing takes), and its frequency (how many swings per unit time it makes). Each is treated in its own subsection below, and a fourth subs …