Fourier Series
x ( t ) = ∑ n = 0 ∞ a n c o s ( ( 2 π m t ) / t ) {\displaystyle x(t)=\sum _{n=0}^{\infty }a_{n}cos((2\pi mt)/t)}
2 T ∑ n = 1 ∞ s i n ( 2 π n t T ) {\displaystyle \ {\frac {2}{T}}\sum _{n=1}^{\infty }sin{\bigg (}{\frac {2\pi nt}{T}}{\bigg )}\!}
