Suppose $S =\displaystyle\sum _ { n = 1 } ^ { \infty } a _ { n }$ is a convergent series and $a_n≠ 0$ or any $n$. Explain why the sequence  $T =\displaystyle\sum _ { n = 1 } ^ { \infty } \frac { 1 } { a _ { n } }$  must diverge.