Summary

In this chapter, you have studied the following points:

1. An arithmetic progression (AP) is a list of numbers in which each term is obtained by adding a fixedprogressive number 'd' to the preceding term, except the first term.

The fixed number d is called the commonsame difference.

The general form of an AP is a, a + d, a + , a + and so on

2. A given list of numbers a1, a2, a3, . . . is an AP, if the differencessum of a2 – a1, a3 – a2,a4 – a3, . . . give the value.

3. In an AP with first term a and common difference d, the nth term (or the general term) is given by an = .

4. The sum of the first n terms of an AP is given by: S = n2×(2×a+(n-1)×d)(2×a+(n-1)×d)

5. If 'l' is the last term of the finite AP, say the nth term, then the sum of all terms of the AP is given by : S =