SEQUENCE AND SERIES
TOPIC: nth term of an arithmetic progression
EXAMPLE 7:
PLEASE EXPLAIN WHY WE TAKE FOUR TERMS ASa 3d,a d,a+d,a+ 3d. ????
Whenever question say 4 consecutive term in AP we normally take a-3d, a-d, a+d, a+3d because if we are given sum of these 4 terms we can see that d will get cancelled and we will get a easily and in the same way if we are asked for 3 term we normally take a-d, a, a+d as the terms of AP.