傅里叶系数公式推导的一个注记

A Comment on the Deduction of Fourier Coefficient Formula

指出现行教材中推导傅里叶系数公式的三种方法,并对每种方法进行点评,在此基础上,从逼近论的角度出发,应用多元函数极值的相关知识,提出了傅里叶系数公式的另一种推导方法,克服了现行分析教材在处理这个问题上的不足、缺陷。

By means of approximation theory, applying relevant knowledge of extremum value of multivariate function, a kind of rigorous deducing method of Fourier coefficient formula is presented. It overcomes the deficiency about this issue in present text book.