\(
\newcommand{\cat}[1] {\mathrm{#1}}
\newcommand{\catobj}[1] {\operatorname{Obj}(\mathrm{#1})}
\newcommand{\cathom}[1] {\operatorname{Hom}_{\cat{#1}}}
\newcommand{\multiBetaReduction}[0] {\twoheadrightarrow_{\beta}}
\newcommand{\betaReduction}[0] {\rightarrow_{\beta}}
\newcommand{\betaEq}[0] {=_{\beta}}
\newcommand{\string}[1] {\texttt{"}\mathtt{#1}\texttt{"}}
\newcommand{\symbolq}[1] {\texttt{`}\mathtt{#1}\texttt{'}}
\newcommand{\groupMul}[1] { \cdot_{\small{#1}}}
\newcommand{\groupAdd}[1] { +_{\small{#1}}}
\newcommand{\inv}[1] {#1^{-1} }
\newcommand{\bm}[1] { \boldsymbol{#1} }
\require{physics}
\require{ams}
\require{mathtools}
\)
Math and science::Analysis::Tao::07. Series
Ratio test
Let \( \sum_{n=m}^{\infty}a_n \) be a series of non-zero numbers.
- If [...], then the series \( \sum_{n=m}^{\infty}a_n \)
is absolutely convergent (hence conditionally convergent).
- If [...], then the series \( \sum_{n=m}^{\infty}a_n \)
is not conditionally convergent (hence not absolutely convergent).
- Otherwise, we cannot assert any conclusion.
The non-zero requirement is needed to avoid a division by zero.
