https://blog.csdn.net/lanchunhui/article/details/50482842
凸函数与简森不等式（Jensen's inequality）
转载于:https://www.cnblogs.com/xiaoshayu520ly/p/9471236.html
https://blog.csdn.net/lanchunhui/article/details/50482842
转载于:https://www.cnblogs.com/xiaoshayu520ly/p/9471236.html