Recent content by brush

Thank you for the reply, yyat! :smile: The confusion I was having was because I kept getting different results from the ratio and root test, but I have figured out what I was doing wrong. In the case above, both the root and ratio tests should yield (I think): \left|x\right| = 1

So, for instance, how do I determine the radius of convergence of: \sum^{\infty}_{n=0}\left(\frac{x^{n}}{n^{2}+1}\right) Thanks again :smile:

Hi everyone :smile: When determining the radius of convergence of a power series, when should I use the ratio (a[sub n+1] / a[sub n]) test versus the root (|a[sub n]|^(1/n)) test? I know that I'm supposed to use the ratio only when there are factorials, but other than that, are these tests...