Show that the sequence defined byis an A.P., find its common difference.
Put n = 1
A1= 5(1) – 7
= -2
Put n = 2
A2= 5(2) – 7
= 10 – 7 = 3
Put n = 3
A3= 5(3) – 7
= 15 – 7 = 8
Common difference, d1= a2 – a1= 3 – (-2) = 5
Common difference, d2= a3 – a2= 8 – 3 = 5
Since, d1 = d2 and Common difference = 5
Therefore, it’s an A.P.