For each of the following series, tell whether or not you can apply the 3-condition test (i.e. the alternating series test). If you can apply this test, enter D if the series diverges, or C if the series converges. If you can't apply this test (even if you know how the series behaves by some other test), enter N.
1. $\displaystyle \sum_{n=1}^\infty \frac{(-1)^n}{n^{2}+5}$
2. $\displaystyle \sum_{n=1}^\infty \frac{(-1)^{n}cos(n \pi)}{n^5}$
3. $\displaystyle \sum_{n=1}^\infty \frac{(-1)^{n}e^n}{n!}$
4. $\displaystyle \sum_{n=1}^\infty \frac{(-1)^{n}n^n}{n!}$
5. $\displaystyle \sum_{n=1}^\infty \frac{(-1)^{n}n!}{n^n}$
6. $\displaystyle \sum_{n=1}^\infty \frac{(-1)^{n}n!}{e^n}$