The iterative methods are a group of numerical methods that improve approximative solutions of a linear system, repetitively, such that converge to the exact solution.

• 关于青少年偏差行为的成因众多，而理性选择理论提供一个很好的解释：偏差行为的决策机制和其他行为相同，是基于理性所做出的决定。