Question
Question: If 'd' is the common difference of an A.P. then-...
If 'd' is the common difference of an A.P. then-
A
d = Sn –Sn–1 + Sn–2
B
d = Sn –2. Sn–1 – Sn–2
C
d = Sn – 2. Sn–1 + Sn–2
D
None of these
Answer
d = Sn – 2. Sn–1 + Sn–2
Explanation
Solution
Sn –2. Sn–1 + Sn–2
= (Sn – Sn–1) – (Sn–1 – Sn–2)
= tn – tn–1 = d