Schlömilch's_series
Schlömilch's series
Fourier series type expansion
Schlömilch's series is a Fourier series type expansion of twice continuously differentiable function in the interval in terms of the Bessel function of the first kind, named after the German mathematician Oskar Schlömilch, who derived the series in 1857.[1][2][3][4][5] The real-valued function has the following expansion:
where