With the help of Newtonformula and Vieta theorem, iterative method was used to solve problems of power sum.
借助牛顿公式和韦达定理，采用迭代的方法求解类似于自然数等幂和的问题。
2
The quasi-Newton method was applied to solving the augmented Lagrangian function of nonlinear programming problems. Further, the quasi-Newtonformula was given.
应用拟牛顿算法求解非线性规划问题的增广拉格朗日函数，并给出了相应的拟牛顿公式。
3
From Newtonformula and its image, this essay discusses the longitudinal conjugated property of ideal optical system and explains the practical applications by giving examples.