Question

if the sum of n terms of an AP is n(2n+1) then find the series​

Answer 1

Step-by-step explanation:

$sn = n(2n + 1) \\ = > a = s1 = 1(2 \times 1 + 1) = 3 \\ s2 = s3 - s2 \\ = 3(6 + 1) - 2(4 + 1) \\ = 21 - 10 \\ = 11 \\ d = 11 - 3 = 8$

Ap= 3,11,19,27.......∞