A function f: R arrow R is periodic iff there is a real number h does not equal such that f(x+h)=f(x) for all x E R. Prove that if f: R arrow R is periodic and continuous, then f is uniformly continuous.
Explanation / Answer
Assume f:R->R is continuous and periodic with fundamental period p. Boundedness: Let x0 in R be arbitrary. The interval [x0, x0+p] is closed. As f is continuous on [x0,x0+p], the Extreme Value Theorem ensures that f attains a maximum value M and minimum value m on [x0,x0+p]. Hence |f(x)| 0 (some delta that can depend on x), such that for all y such that |x-y|