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

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

Algebraic form of an arithmetic sequence is 6n+3 a) Find the sum of first 20 terms of the sequence: b) Write the algebraic expression of the sum.

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

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 to n terms of a sequence be n^(2)+2n then prove tht the sequence is an A.P.

A sequence is called an A.P if the difference of a term and the previous term is always same i.e if a_(n+1)- a_(n)= constant ( common difference ) for all n in N For an A.P whose first term is 'a ' and common difference is d has n^(th) term as t_n=a+(n-1)d Sum of n terms of an A.P. whose first term is a, last term is l and common difference is d is S_(n) = n/2 (2a +(n-1)d)=n/2 (a+a+(n-1)d)= n/2 (a+l) If sum of n terms S_n for a sequence is given by S_n=An^2+Bn+C , then sequence is an A.P. whose common difference is

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

If sum of n terms of a sequence is given by S_(n)=3n^(2)-5n+7&t_(r) represents its r^(th) term then