Question

State whether the following sequence is an A.P. or not.

1,3,6,10,...... 

Answer 1

1,3,6,10,......

Here , t₁ = 1, t₂ =3, t₃ = 6, t₄= 10. 

∴ t₂ + t₁ = 3 - 1=2

    t₃ - t₂ = 6 - 3 = 3

    t₄ - t₃ = 10 - 6 = 4

∴ The difference between any two consecutive terms of the sequence is not constant ∴ it is not an A.D.