Question

For both of the following answer blanks, decide whether the given sequence or series is convergent or divergent. If convergent, enter the limit (for a sequence) or the sum (for a series). If divergent, enter INF if it diverges to infinity, MINF if it diverges to minus infinity, or DIV otherwise.

A_n=(9^n)/(-2n+9)

The sequence {A_n}?

Answer 1

It's divergent, I know that for n=1 to infinity

Answer 2

Looking at these graphs, I'd go with MINF.

See what you think:

http://www.wolframalpha.com/input/?i=%3D%289%5En%29%2F%28-2n%2B9%29
and
http://www.wolframalpha.com/input/?i=Series+%289%5En%29%2F%28-2n%2B9%29

Answer 3

It's divergent all right, and in fact, properly divergent :)

Answer 4

it says its wrong ;/

Answer 5

What was given as the correct answer? @monroe17

Answer 6

It won't show me, I have unlimited attempts until the assignment closes.. I have no idea besides it diverges.

Answer 7

@monroe17 I think we looked at the series and not the sequence. Hold on. I sent a help request to a Calculus friend. When does the assignment close?

Answer 8

11:59pm and it's 7:14pm

Answer 9

Wouldn't it be
\[\lim_{n \rightarrow -\infty} \frac{9^n}{9-2n}=-\infty\]
cause the value gonna get large and in a negative way because of -2n

Answer 10

@monroe17

From @PhoneAFriend

" I wrote out a few terms and the sequence became negatively large very quickly. Check it on my TI-89 and found that by the time we looked at term 100 (or 101, depending on counting technique), the value was already around -1.4 x 10^93. So, the sequence seems to be heading toward negative infinity. Does that seem logical to you?"