摘要
一元微分学中 ,实际问题的最大 (小 )值的解法是将中间变量显化后代到目标方程中 ,将目标变量由自变量直接表达 ,使问题转化为一元显式函数的最大 (小 )值 ,但该解法对于一些习题计算繁琐 .这实际也是一种条件极值 .多元微分学使用拉格朗日乘数法解决 ,拉格朗日乘数法在一元微分学中不能使用 .本文从拉格朗日乘数法的证明中得到启示 ,并结合日常教学总结归纳了一种解法 ,可使计算简便 .
In one unknown differential calculus,the solution of extremum for practical question is to make the middle variable clear and put it into the objective expression.That is to say to express objective variable by independent variable directly and to change the question into the extremum of one unknown explicit funxtion.However,the above solution is complex for some exercises.In fact,it is a kind of conditional extremum.In differential calculus of several variable.Lagrang’s method of multiplies is used,which cannot be used in one unknown differential calculus.Inspired from the proof of Lagrang’s method of multiplies,a new method was presented which can make the calculation simplify.
出处
《天津城市建设学院学报》
CAS
2000年第3期219-221,共3页
Journal of Tianjin Institute of Urban Construction
关键词
条件极值
目标函数
不替换解法
微分学
conditional extremum
objective function
middle variable
lagrange’s method of multiplies
