文［１］给出了判定周期函数的一组三个定理，读后很受启发．用这组定理可以正确地判定一些周期函数，但其中关于最小正周期的部分内容却存在疏漏，下面加以完善．原文定理１　设λ为非零常数，若对函数ｆ（ｘ）定义域中的任意ｘ，恒有ｆ（ｘ＋λ）＝Ｍ（ｆ（ｘ））①（其中Ｍ The paper [1] gives a set of three theorems that determine the periodic function. It is very inspired after reading. This set of theorems can be used to correctly determine some periodic functions, but there are omissions in the part of the minimum positive period. The original theorem 1 Let λ be a non-zero constant. If we define an arbitrary x in the domain for the function f(x), we have f(x+λ)=M(f(x))1 (where M)