code: function SimpsonRecursive(func, a, b, whole, eps) {
    var c = a + b;
    var left = SimpsonDef(func, a, c);
    var right = SimpsonDef(func, c, b);
  
    if (Math.abs(left + right - whole) <= 15 * eps) {
      return left + right + (left + right - whole) / 15;
    } else {
      return SimpsonRecursive(func, a, c, eps / 2, left) + SimpsonRecursive(func, c, b, eps / 2, right);
    }
  }
docs: Helper function in calculating integral of a function
  from a to b using simpson quadrature.  Manages recursive
  investigation, handling evaluations within an error bound.
  
  @param {Function} math function to be evaluated.
  @param {Number} point to initiate evaluation.
  @param {Number} point to complete evaluation.
  @param {Number} total value.
  @param {Number} Error bound (epsilon).
  @return {Number} recursive evaluation of left and right side.