Question

What is the formula for the arithmetic sequence if the sum of the same sequence is given by Sn= 2n + 3n2?

Answer 1

Answer:

6n-1

Step-by-step explanation:

sn= 3n^2+2n

so an= sn-s(n-1)

an= 3n^2+2n-(3(n-1)^2+2(n-1))

= 3n^2+2n-(3(n^2-2n+1)+2n-2)

=3n^2+2n-3n^2+6n-3-2n+2= 6n-1