Question

Which of the following sequences are A.P.? If they are A.P. find the common difference.

–10, –6, –2, 2,...

Answer 1

–10, –6, –2, 2...

t₁ = -10, t₂ = -6, t₃ = -2, t₄ = 2

d₁ = t₂ - t₁

= -6 - (-10)

= -6 + 10

= 4

d₂ = t₃ - t₂

= -2 - (-6)

= -2 + 6

= 4

d₃ = t₄ - t₃

= 2 - (-2)

= 2 + 2

= 4

d₁ = d₂ = d₃ = 4

The given sequence is an A.P.