The sine wave is important in physics because it retains its wave shape when added to another sine wave of the same frequency and arbitrary phase and magnitude. It is the only periodic waveform that has this property.This property leads to its importance in Fourier analysis and makes it acoustically unique.his wave pattern occurs often in nature, including ocean waves, sound waves, and light waves. A cosine wave is said to be sinusoidal, because which is also a sine wave with a phase-shift of π/2 radians.