code: def binormal_curve_single(obj, u, normalize):
      
      # Cross product of tangent and normal vectors gives binormal vector
      tan_vector = tangent_curve_single(obj, u, normalize)
      norm_vector = normal_curve_single(obj, u, normalize)
  
      point = tan_vector[0]
      vector = linalg.vector_cross(tan_vector[1], norm_vector[1])
      vector = linalg.vector_normalize(vector) if normalize else vector
  
      return tuple(point), tuple(vector)
docs: Evaluates the curve binormal vector at the given u parameter.
  
      Curve binormal is the cross product of the normal and the tangent vectors.
      The output returns a list containing the starting point (i.e. origin) of the vector and the vector itself.
  
      :param obj: input curve
      :type obj: abstract.Curve
      :param u: parameter
      :type u: float
      :param normalize: if True, the returned vector is converted to a unit vector
      :type normalize: bool
      :return: a list containing "point" and "vector" pairs
      :rtype: tuple