Question

Find the common difference of the A.P, if the sum of first n terms of the sequence is given by $S_n=n^2+2n+6$?

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is B

2

The nth term of the progression is given by $Sn-S(n-1)=n^2+2n+6-(n-1{)}^2-2(n-1)-6=2n+1$

Hence, common difference = 2