Question

If the sum of n terms of an AP is 4

2 + 2, then find the nth term of the AP.​

Answer 1

Step-by-step explanation:

S

n

=4n

2

+2n

S

n−1

=4(n−1)

2

+2(n−1)

T

n

=S

n

−S

n−1

⇒T

n

=(4n

2

+2n)−(4(n−1)

2

+2(n−1))

=4(n

2

+(n−1)

2

)+2(n−n+1)

=4((n−n+1)(n+n−1))+2 on expanding

=4(2n−1)+2

=8n−4+2=8n−2