Question

In an AP, if sum of first term is n square+ 2n, find its first term and
common difference.​

Answer 1

Step-by-step explanation:

$an = {n}^{2} + 2n$

$a1 = {1}^{2} + 2 \times 1 = 3$

a2=2^2+2×2=8

so first term is 3 and

common difference is

a2-a1=8-3=5