Question

If Sn = 4n2 – 3n, then the common difference of the AP is
: (A) 8
(B) –8
(C) 7
(D) 5​

Answer 1

Answer:

(A) iZ d crrct answer

hope it was somehow helpful for u?!♥

Answer 2

$\huge\dag\mathbb\red{Solution} \dag$

$S_{n} = {4n}^{2} −3n$

$Now, S_{n} +1=4 {(n + 1)}^{2} −3(n+1)$

$We \: know \: that, t_{n + 1}=S _{s + 1} −S_{n}$

$t_{n + 1} =4 {n}^{2} +5n+1−4 {n}^{2} +3n$

$t_{n + 1} =8n+1$

$Thus \:  t_{n + 1} \:  is \: linear \: equation \: of  \: n  \\ \\ hence \: it \: is \: an \:  A.P\\ \\ Now  \: t_{n + 1} =8n+1 \\ \\ comlplaning \: with  \: a_{n + 1} =a+(n−1)  \\ \\ a=1   and   d=8$

common difference is 8 .

option (A) ✔