因此,一个多变量的函数没有通常的导数。
The teaching of function of several variables is a difficult point in higher mathematics teaching.求最值问题是中等数学永恒的话题,其中,多元函数求最值是难点。
Through the quadratic form theory, another solution to the extremum problem of function of several variables is given.利用二次型的理论,给出解决多元函数极值问题的另一种方法。