关于周期函数的定义域和图象的特征，文［１］、文［２］分别进行了论述，读后深受启发．但两文中所给出的结论都值得商榷．现就这两个问题谈点我们的认识，与广大同仁探讨．一、关于周期函数的定义域如前文所述，按现行教材中周期函数的定义，文［１］中给出的命题：“周期函 Regarding the definition of the periodic function and the features of the image, the paper [1] and [2] were separately discussed and deeply enlightened after reading. However, the conclusions given in both articles are worth discussing. We now discuss our understanding of these two issues and discuss it with our colleagues. First, the definition of the domain of the periodic function As mentioned earlier, according to the definition of the periodic function in the current textbook, the proposition given in [1]: "The periodical letter