If the sum of first m terms of an AP is (2m2 + 3m) then what is its second term?
Let Sn denotes the sum of first n terms of an AP.
Sum of first m terms = Sm = 2m2 + 3m
Then nth term is given by: an = Sn - Sn - 1
We need to find the 2nd term, so put n = 2, we get
a2 = S2 - S1
= (2(2)2 + 3(2)) - (2(1)2 + 3(1))
= 14 - 5
= 9
∴ the second term of the AP is 9.