Find the second term if sum of the 'n' tem of an AP is `2n^2 +1` .

If sum of first n terms of an AP is 2n^(2)+5n. Then find S_(20)

Find the sum of 'n' terms of an A.P. whose nth term is 2n+1.

Find the sum of 'n' terms of an A.P. whose nth term is 2n+1.

Find te rth term of an AP sum of whose first n terms is 2n+3n^(2).

Find the rth term of an AP sum of whose first n terms is 2n+3n^(2).

The sum of n terms of an A.P. is 3n^2 + 4n . Find the A.P.

Given sum of the first n terms of an A.P is 2n+ 3n^(2) . Another A.P is formed with the same first term and is double the common difference, the sum of n terms of the new A.P. is

Given sum of the first n terms of an A.P. is 2n+3n^(2) Another A.P .is formed with the same first.term and double of the common difference,the sum of n terms of the new A.P. is -