Ratio TestIn Probability, Lโกlimโกnโโโฃan+1anโฃL \equiv \lim_{n \to \infty} |{a_{n+1} \over a_n}|Lโกnโโlimโโฃanโan+1โโโฃ L<1L < 1L<1: Series converges absolutely. L>1L > 1L>1: Series diverges. L=1L = 1L=1: Test fails.