Question

If sum of n terms of a sequence is given by S_n = 2n² + 3n, find its 50^th term.

Answer 1

Let t n is nth term of the sequence so t_n = s_n – s_{n – 1}. 

= 2n² + 3n – 2(n – 1)² – 3(n – 1) 

= 4n + 1 

so t₅₀ = 201.