Question

if the sum of first n terms of an AP is 4n- n² . find its nth term

Answer 1

Answer:

2

Step-by-step explanation:

first

let's take a1 as 1,therefore,

4n-n^2=4(1)-(1)^2

=4-1

=3

then,take,

a2=2

4n-n^2

=4(2)-(2)^2

=8-4

=4

then subtract s2-s1,we get a2=1

by subtracting s1 which is equal to a1 with s1 we get -2 which is common difference

then apply the formula of

an=a+(n-1)d

where an=1

a=3

d=-2

find the value of n by substituting the values and simplification