Question

SERIES: CONVERGENCE, DIVERGENCE
http://i1084.photobucket.com/albums/j409/QRAWarrior/MATA36-MQ6.png

Answer 1

I got the summation for a_n, but how do I get a_n?

Answer 2

Romero, how did you colour your avatar blue? @Romero

Answer 3

Photoshop

Answer 4

\[\Large s_{n} = a_{1} + a_{2} + ... + a_{n-1} + a_{n} = 7 - n3^{-n}\]\[\Large s_{n-1} = a_{1}+a_{2}+...+a_{n-1} = 7 - (n-1)3^{-(n-1)}\]
Hint: try finding the value of \(\Large s_{n} - s_{n-1}\)

Answer 5

@FoolAroundMath why would you do that?

Answer 6

Why does a_n = s_n - s_n-1?