Question

If the sum of the first n terms of an AP is 4n -nsquare what is the first term ? What is the sum of first two terms ? What is the second term ? Similarly find the 3rd the 10 th and the nth terms

Answer 1

When Snth term is given then

Anth = Sn-Sn-1

First term= S1-S0

=4 (1)-(1)^2

=3

S2= 4 (2)-(2)^2

=8-4

=4

A3= 4 (3)-3^2

=-1

A10= 4 (10)-10^2

=60