Question

If the sum of m terms of an ap is 2n^2 +5 then find it's nth term

Answer 1

s(n-1)=2(n-1)2 +5(n-1)
= 2(n2+1-2n) +5n-5
= 2n2+2-4n +5n-5
=2n2+n+-3
an= Sn-S(n-1)
an= 2n2+5n-(2n2+3n+3)
an= 2n2+5n-2n2-n+3
an=4n+3