ABSTRACT
The simplest periodic function is the sine (or cosine) function, A sin(ωt + α) (or A cos(ωt + α)), where ω is the angular frequency related to the period by the relationship
ω =
pi2 T
(9.1)
(quantity f = 1/T is called frequency, constant α is called phase). With these simple periodic functions more complex periodic functions can be con-
structed, as was noted by the French mathematician Joseph Fourier. For example, if we add the functions
= = ω + α = ω + α
= ω + α
, sin( ), sin(2 ),
sin(3 ),...