Find the nth term of the following A.P.'s:

1.2, 2.3, 3.4, 4.5, ...

Formula Used.

d_n = a_{n + 1} – a_n

a_n = a + (n–1)d

In the above sequence,

a = 1.2;

d₁ = a₂–a₁ = 2.3–1.2 = 1.1

d₂ = a₃–a₂ = 3.4–2.3 = 1.1

d₃ = a₄–a₃ = 4.5–3.4 = 1.1

The difference in sequence is same and comes to be (1.1).

∴ The above sequence is A.P

The n^th term of A.P is a_n = a + (n–1)d

a_n = a + (n–1)d = 1.2 + (n–1)(1.1)

= 1.2 + 1.1n–1.1

= 0.1 + 1.1n