I first thought it was $$x\left(t\right)=\frac{4}{T}t$$ for $$0<t<T/4$$
But that would be the case if it wasn't periodic, then i thought that it was:
$x\left(t\right)=\frac{4}{T}\left(t-T\right)$
But i'm not sure, and don't know how to plot it on graphing software to test it out. Can someone help me out?
EDIT: The problem I had at hand is to find the Fourier series for this function and I tried for both the functions I had written here earlier, but neither got me the right solution, so I'm not sure now.
Here is what I did so far:
