# What do you do if the Alternating Series Test fails?

In most cases, an alternation series ${\sum}_{n = 0}^{\infty} {\left(- 1\right)}^{n} {b}_{n}$ fails Alternating Series Test by violating ${\lim}_{n \to \infty} {b}_{n} = 0$. If that is the case, you may conclude that the series diverges by Divergence (Nth Term) Test.