Question

Find the an of A. P if Sn=n^2+n

Answer 1

Answer:

Step-by-step explanation:

Sn = n^2 + n

Let n be 1

S1= 1 +1 = 2 = a1

S2 = 4 +2 = 6

S2 - S1 = a2                       (sn - s(n-1) = an)

6-2= 4

a2 = 4

a = 2

d = 2

an = 2+ (n-1)2

an = 2+ 2n-2

an = 2n