Question

in an a.p ., prove that d= Sn - 2Sn-1 + Sn-2

Answer 1

Iam not getting this answer.If I get, I'LL definitely tell you.

Answer 2

I got this anwer put the values oh Sn and all will be cut out except d and d=d will be proved okk but listen put n -1 and n-2 in that case where Sn -1 and 2 has written than your answer will be come