Convergence Test: Solving Homework on (n!)/(2n)!

[lmannoia]

Homework Statement

It's from sum (n=1, to infinity.. I apologize for not knowing how to type it in properly!) of (n!)/(2n)!

Homework Equations

The Attempt at a Solution

We're supposed to use either the Root Test or the Ratio Test to determine if the series converges or not. My problem is that I don't know how to break up (2n!) so that it'll cancel with (n!). Any hints are appreciated. Thank you!

 

[jgens]

If you use the ratio test, you shouldn't have to worry too much about breaking up the (2n)! term.

 

[micromass]

Hint: when you see factorials, always try the ratio test.

 

[lmannoia]

Looking at it again, I figured it out. Thanks for the hint, too!