Question

1 If the sum to n terms of a sequence is 2n2 + 4. Find its nth term. Is
sequence an A.P. ?​

Answer 1

2n^2+4=n/2(2a+(n-1) d)

4n^2+8=n(2a+dn-d)

4n^2+8=2an+dn^2-nd

n^2(4-d) -n(d-a) +8=0

Solve n by sridhar

and then find

Tn,=a+(n-1) d