I have redone this problem many times, and can't seem to figure it out!
The problem is to use the ratio test to find the limit and convergence of this series:
Now, using the ratio test, I come up with this:
How do I expand this to cancel the series out? This is what I tried:
However, when I cancel everything out, I get which results in the limit being 0.
But 0 is not the correct limit.
Any help would be very appreciated!
I think the problem is that I really don't understand factorials very well...I'm not sure.
Thank you for your reply though.
Edit: After looking at it, the only part I don't understand is after the first equals sign. Where did that n!(n+3)! on the bottom come from? The rest I understand.