摘要
分别给出了P0(x0,y0)的l0珒正方向δ邻域和l0珒负方向δ邻域的定义,用方向导数表示了二元函数的泰勒公式,使之与一元函数的泰勒公式有统一的形式;并利用二元函数泰勒公式的方向导数形式给出了二元函数取得极值的3个充分条件,使之与一元函数取得极值的3个充分条件相对应.
In this paper,the definition of positive direction neighborhood of a point P0(x0,y0) and its negative direction neighborhood are given.Taylor's formula of two-variable function is given by the use of directional derivative,which is in accord with Taylor's formula of one-variable function.Meanwhile,three sufficient conditions of two-variable function extreme value are given with directional derivative of Taylor's formula of two-variable function,which are in accord with one-variable function.
出处
《平顶山学院学报》
2011年第5期11-14,20,共5页
Journal of Pingdingshan University
关键词
方向导数
极值
二元函数
泰勒公式
directional derivative
extreme value
two-variable function
Taylor's formula