一、週期函数的定义有一个不为0的实数p对于函数f(x)使得等式f(x)=f(x+p)成立,则函数f(x)称为週期函数,而常数p称为此函数的週期。由週期函数的定义可以直接推得:若p是函数f(x)的週期,則数2p,3p,…,—p, First, the definition of the periodic function has a real number p that is not zero. For the function f(x), the equation f(x)=f(x+p) holds, then the function f(x) is called the periodic function, and the constant p This cycle is called this function. From the definition of the periodic function can be directly derived: If p is the cycle of the function f(x), then the number 2p, 3p, ..., -p,