说明：  在科学与工程计算中，经常遇到求解非线性方程组的问题；非线性方程组在收敛速度及收敛性比线性方程组要差，特别对于非凸的非线性方程组，其求解更是困难。下面简要介绍非线性方程组的三种解法——牛顿法、拟牛顿法、同伦算法，分析三种解法的适用性，并附Matlab原程序。
(Scientific and engineering computing, often encounter the problem of solving nonlinear equations speed of convergence of nonlinear equations and linear equations worse than convergence, especially for non-convex nonlinear equations, which is even more difficult to solve . The following briefly describes three solutions to nonlinear equations- Newton method, quasi-Newton method, homotopy method, the applicability of the three solutions, along with Matlab original program.)