+A **Fourier Series** unravels complex [periodic functions](/wiki/periodic_function) into a harmonious sum of simple sine and cosine [waves](/wiki/wave). It acts as a mathematical lens, revealing the hidden frequencies that compose any repeating signal, from sound to light.
+## See also
+- [Harmonic Analysis](/wiki/harmonic_analysis)
+- [Fast Fourier Transform](/wiki/fast_fourier_transform)
+- [Signal Processing](/wiki/signal_processing)
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