Question

if An=4n-3 then Sn is equal to?

this question is from the chapter arithmetic progression ​

Answer 1

Answer:

hope it's clear to you mate

Answer 2

Terms are
1,5,9,——-
S = n/2 {2a+ (n-1)d}
= n/2 {2+ ( n-1)4}
= n/2 (4n-2)
= n(2n-1)