sinusoidisarja
A sinusoidisarja, or sinusoidal series, is a mathematical concept referring to the representation of a function or signal as a sum of sinusoidal functions. These functions are typically of the form $A \sin(kx + \phi)$ or $A \cos(kx + \phi)$, where $A$ is the amplitude, $k$ is the wave number or angular frequency, $x$ is the independent variable (often time or position), and $\phi$ is the phase shift.
The most prominent example of a sinusoidal series is the Fourier series, which allows for the representation
The concept extends to other forms of sinusoidal representations, such as in the context of wave phenomena.