Answer:
[tex]{ \rm{x(t) = a_{0} + \sum a_{k} \cos \omega t + \sum b _{k} \sin \omega t }}[/tex]
[tex]{ \tt{ a_{0} = \frac{2}{t} \int x(t) \: dx}} \\ \\ { \tt{ a_{k} = \frac{1}{t} \int x(t) \cos \omega t \: dx }} \\ \\ { \tt{ b_{k} = \frac{1}{t} \int x(t) \sin \omega t \: dx }}[/tex]
