ARITHMETIC PROGRESSION Class 10 Chapter 5 Class 11 Chapter 9 Sequence and Series Main Points to be discussed here Definition of Sequence, Series and Progression. Concept of Arithmetic Progression, General AP Sequence, General Term, Sum of n terms in an AP and Arithmetic Mean. Finite and Infinite AP Three terms in AP, Four terms in AP and five terms in an AP. Properties of Arithmetic Mean Sequence : An arrangement of numbers in a definite order according to some rule is called a sequence. The terms of the sequence are denoted by t 1 , t 2 , t 3 , t 4 , ……….. or a 1 , a 2 , a 3 , a 4 , …………………. Example: 2, 4, 6, 10, 12, 14, ................ Series : If the terms of a sequence are connected by plus (or minus) sign, is called a series. Example: 2 + 4 + 6 + 10 + 12 + 14 + ................ Progression: A sequence following some definite rule is called a progression. Arithmetic Progression A sequence is called arithmetic progression if the difference of a term and i