The sum of n terms of a series is `(3n^(2)+2n)`. Prove that it is an A.P.

The sum of n terms of a series is n(n+1) . Prove that it is an A.P. also find its 10th term.

The sum of n terms of a series is (2n^(2)+n) .Show that it is an A.P. .

(a) The sum of 'n' terms of a progression is n(n + 1). Prove that it is an A..P. Also find its 10th term. (b) The sum of 'n' terms of a progression is (3n^(2) - 5n). Prove that it is an A.P. (c) If the sum of n terms of a series is (5n^(2) + 3n) then find its first five terms.

The sum of n terms of an A.P. series is (n^(2) + 2n) for all values of n. Find the first 3 terms of the series:

The sum of n terms of an A.P. is 4n^(2) + 5n. Find the series.

If the sum to n terms of a sequence be n^2+2n then prove that the sequence is an A.P.

If the sum of n terms of an A.P. is 2n^2+3n then write its nth term.

If the sum of n terms of an A.P. is 2n^(2)+5n , then its n^(th) term

The sum of n terms of an A.P. is (n^(2)+5n). Its common difference is :

If the sum of first n terms of an A.P. is an^(2) + bn and n^(th) term is An + B then