As an exercise we have to calculate the fourier series of |sin(x)| (was no problem) and after that we are meant to show that this series converges uniformly towards |sin(x)|.
After thinking about it for a while and not coming up with anything productive except that it converges for x=0 and that the series converges uniformly towards something at all, I dont have any more ideas.
Sadly we can't use stuff like the rule for uniform convergence when the function is continuosly differentiable because we didn't learn that yet.
Any hint or solution would be appreciated, cheers :)
Edit: Maybe I should mention that we use sines and cosines and not the complex exp-function for the series.