Why in fourier series constant is divided by two?

Answer 1

In Fourier series, the constant term, or the average value of the function over one period, is divided by two when computing the Fourier coefficients. This is because the constant term corresponds to the zero-frequency component, which represents the average value of the periodic function. When calculating the Fourier series, the coefficients are derived from integrals that include the full period of the function, leading to the factor of ( \frac{1}{2} ) for the constant term to ensure accurate representation. This adjustment maintains the overall balance of the series in reconstructing the original function.