The general form of an Arithmetic Progression is a, a d, a 2d, a 3d and so on. Thus nth term of an AP series is Tn = a (n - 1) d, where Tn = nth term and a = first term. Here d = common difference = Tn - Tn-1. The sum of n terms is also equal to the formula where l is the last term.

Subsequently, question is, what is a common difference in arithmetic sequences? An arithmetic sequence is a string of numbers where each number is the previous number plus a constant, called the common difference. To find the common difference we take any pair of successive numbers, and we subtract the first from the second.

In this way, what is a recursive formula?

A recursive formula designates the starting term, a1, and the nth term of the sequence, an , as an expression containing the previous term (the term before it), an-1. The process of recursion can be thought of as climbing a ladder.

Which of the sequences is an arithmetic sequence?

An arithmetic sequence is a sequence where the difference between any two consecutive terms is a constant. An explicit formula for an arithmetic sequence with common difference d is given by an=a1 d(n−1) a n = a 1 d ( n − 1 ) . An explicit formula can be used to find the number of terms in a sequence.