code: def sin_3(a=1):
      r
  
      def lhs(x):
          return x/(a**2 + x**2)
  
      def rhs(b):
          return np.pi*np.exp(-a*b)/2
  
      return Ghosh('sin', lhs, rhs)
docs: r"""Fourier sine transform pair sin_3 ([Ande75]_).