Cosine Wave
Cosine Wave :
A cosine wave is a signal waveform with a shape identical to that of a sine wave, except each point on the cosine wave occurs exactly 1/4 cycle earlier than the corresponding point on the sine wave. A cosine wave and its corresponding sine wave have the same frequency, but the cosine wave leads the sine wave by 90 degrees of phase. In most practical situations, a lone cosine wave is the same as a lone sine wave; phase generally has meaning only when two or more waves having identical frequencies are compared. The distinction between sine and cosine waves is important in Fourier analysis, where complex waveforms are defined in terms of constituent sine and cosine waves, and in Fourier synthesis, where complex waveforms are electronically built up from sine and cosine waves
