If there are only a limited number of terms in the sequence then it is known as finite Arithmetic Progression.

229, 329, 429, 529, 629

2. Infinite Arithmetic Progression

If there are an infinite number of terms in the sequence then it is known as infinite Arithmetic Progression.

2, 4, 6, 8, 10, 12, 14, 16, 18…..…

The nth term of an Arithmetic Progression

If an is the nth term,a1 is the first term, n is the number of terms in the sequence and d is a common difference then the nth term of an Arithmetic Progression will be

Example

Find the 11th term of the AP: 24, 20, 16,…

Given a = 24, n = 11, d = 20 – 24 = – 4

an = a + (n – 1)d

a11 = 24 + (11-1) – 4

= 24 + (10) – 4 =24 – 40 = -16