Calculus 2, Series Convergence Questions?

[MMhawk607]

I have some problems here with Series and Convergence...

Here are the problems and my guesses at it.

http://img822.imageshack.us/img822/9523/23341530.png

It won't tell me which one is wrong, but it just says one/all is wrong. Any help is appreciated.

Attempts at solving, I tried using ratio test for these but I can't seem to get it. I need more comprehension of these types of problems I know, but these problems are due by tonight.
Alternating series really give me trouble too.

 

[MMhawk607]

OH

It was because of the third problem

sin(3n)/n^2

Is it because

sin(3n) / (n^2) ≤ 1/(n^2)

Therefore the p test makes it absolutely convergent?

I had the other 4 right, I figured that one was A though, is this the reason?

 

[SammyS]

OH

It was because of the third problem

sin(3n)/n^2

Is it because

sin(3n) / (n^2) ≤ 1/(n^2)

Therefore the p test makes it absolutely convergent?

I had the other 4 right, I figured that one was A though, is this the reason?

Hello MMhawk607. Welcome to PF !

Yes, you had #3 wrong .

It is absolutely convergent.

 

[SammyS]

i have some problems here with series and convergence...

Here are the problems and my guesses at it.

http://img822.imageshack.us/img822/9523/23341530.png

it won't tell me which one is wrong, but it just says one/all is wrong. Any help is appreciated.

Attempts at solving, i tried using ratio test for these but i can't seem to get it. I need more comprehension of these types of problems i know, but these problems are due by tonight.
Alternating series really give me trouble too.

...                         .