x(t) = A₁·sin(2π·f₁·t) + A₂·sin(2π·f₂·t) + A₃·sin(2π·f₃·t)
X(f) = ∫ x(t) · e−i2πft dt
→ maps time → frequency
Frequency spectrum |X(f)|
Sine components — click to toggle
Each component is a pure sine wave. The Fourier transform finds how much of each frequency exists in the signal — the tall bars in the spectrum correspond exactly to the active components on the left.