Question

if sum of the n terms of an AP is given by Sn=3n-nsquare find common difference of the AP​

Answer 1

Answer:

d = -2

Step-by-step explanation:

we Sn = 3n-n²

S1 = A1 = 3(1)-(1)² = 2

S2 = 3(2)-(2)² = 6-4 = 2

S3 = 3(3)-(3)² = 9-9 = 0

as, A1 = S1

A2 = S2-S1

A3 = S3-S2

so, A1 = 2

A2 = 2-2 = 0

A3 = 0-2 = -2

so, A.P = 2,0,-2,....... d(common difference) = a2-a1 = a3-a2

so, d = 0-2 = -2

and = -2-0 = -2

so, d = -2 .... ans.