1. The problem statement, all variables and given/known data I have an equation that has the following values at different intervals: It is: r when 0<x<2Pi r - (1)d when 2Pi<x<4Pi r - (2)d when 4Pi<x<6Pi And so on. I want to find a function that encompasses this whole function. Unit functions / discontinuity functions are fine; as long as I can take derivatives in the future. 2. The attempt at a solution The furthest I could get is to define a series as follows: r - n*d when 2nPi < x < 2(n+1)*Pi At this point, my mind thinks discontinuity functions, but those would only work if 'n' was always a constant value, and didn't increase by 1 each iteration. Thank you!