Question

If sum of $n$ terms of a sequence is given by $S_n=2n^2+3n,$ find its ${50}^{th}$ term.

Answer 1

Let $t_n$ is $n^{th}$ term of the sequence so $t_n=S_n-S_{n-1}.$
$=2n_2+3n-2{(n-1)}^2-3(n-1)$
$=4n+1$
so $t_{50}=201.$