牛顿迭代法（Newton s method）又称为牛顿-拉夫逊方法（Newton-Raphson method），它是牛顿在17世纪提出的一种在实数域和复数域上近似求解方程的方法。多数方程不存在求根公式，因此求精确根非常困难，甚至不可能，从而寻找方程的近似根就显得特别重要。-Newton iteration (Newton' s method) is also known as the Newton- Raphson method (Newton-Raphson method), it is proposed by Newton in the 17th century as a real number domain and in the complex field approximation method for solving equations. Root does not exist in most formula equation, it is very difficult for accurate root, if not impossible, in order to find the root on the approximate equation is of particular importance.