牛顿迭代法以微分为基础的，微分就是用直线来代替曲线，由于曲线不规则，那么我们来研究直线代替曲线后，剩下的差值是不是高阶无穷小，使得近似得到所要求得解。-Newton iterative method based on the differential based, differential is in a straight line to replace the curve, due to the irregular curve, we studied line instead of the c