In fact, every periodic signal F with a specific waveform can be expressed as F ( t ) = A w ( φ φ ( t ) ) where w is a "canonical" function of a phase angle in 0 to 2π, that describes just one cycle of that waveform; and A is a scaling factor for the amplitude. (This claim assumes that the starting time t 0 chosen to compute the phase of F corresponds to argument 0 of w .)