Good evening everyone,
I'd like to discuss with you the following exercise :
$\sum\limits_{n=1}^{\infty} (-1)^{n} \frac{n^{2} +3n - \sin(n)}{n^{4}-\arctan(n^{2})}$
I can prove that $\lim\limits_{x \to \infty} a_{n} = 0$ , where $a_{n} = \frac{n^{2} +3n - \sin(n)}{n^{4}-\arctan(n^{2})}$
But I can't still proove its convergence, I'd have used Leibnitz alternating series test (due to $(-1)^{n}$), but I was unable to say $a_{n+1} \leq a_{n}$.
Maybe I could study the Absolute convergence and then by Comparison test find that converges ?
Any help would be appreciated,
Thanks anyway.