Question

Are constant functions periodic? The reason I ask this is because a function is periodic if it has a period but in a constant function the period could be infinitely small.

Answer 1

A function f:R→R is periodic if there exists some number t>0 such that

f(x)=f(x+t)

A constant function is periodic since you can take t=1,t=2, etc. (Hint: Hover over the tag "periodic-functions". What do you see?)

The fundamental period of f is the smallest of such t's. Since t cannot be 0, you are looking for the minimum of (0,∞), which does not exist.

Explanation: