How do I set up the equation of a periodic function?

Question

I have a graph, and by looking at it I can see that the amplitude is 1, the maximum is 1, minimum is 0, and the period is 2. How do I set up the equation? What is the formula?

Answer 1

You have $f(x) = -x +1, x\in[0,1]$ and $f(x) = x-1, x\in[1,2)$

Add that $f$ is $p=2$ periodic and there is your function.