If the sum of n terms of a a sequence is quadraic expression it always repesents an AP .

If the sum of n terms of a sequence is quadratic expression it always represents an AP.

If the sum of n terms of sequence S_(n)=(n)/(n+1)

If the nth term of a sequence is an expressionof first degree in n,show that it is an A.P.

Sum of n Terms of an A.P. | Examples

If the sum to n terms of a sequences is 2n^(2)+4, find its nth.Is this seqwuence as AP?

If the sum of the first four terms of an AP is 40 and the sum of the first fourteen terms of an AP is 280. Find the sum of first n terms of the A.P.

If the sum of the first n terms of a sequence is equal to √ (3/ 2) ( n^ 2 − n ) , then the sum of the squares of these terms is equal to