Alternate representation of sea waves alternate representation of sea waves it is well -known that a Fourier series may be it may represent a periodic signal which contains components at multiples of fundamental frequency of peak frequency or fundamental frequency f naught in a complex form it can be represented as shown in this equation. Wherein a n is nothing but these are the complex Fourier components or Fourier coefficients which are represented as shown here. If eta of t is real then we must have a suffix minus n equal to a suffix n brush up your Fourier series.