This paper carried out Lagrange's to acquire three new proofs and one corollary, final analysis is carried out by two examples. Seek the functional limit by making use of mean value theorem and B.Taylor expansion On Application of Tayler Formulation 利用拉格朗日中值定理、函数的单调性及泰勒中值公式给出了凸函数一个定理的三种新的证明方法,还给出了定理的一个推论,最后给出两个例子对其推论加以应用
Final, the project for applied and development research was been evaluated and selected by using profit and loss value theorem, methods of decision tree and matrix. 最后利用益损值准则法、决策树法、矩阵法对应用开发研究项目进行选择决策。