如何修复此问题？无法显示符号。另外，我无法运行 \begin{cases}

Question

LateX 没有显示我想要的方程式；F(x)= exp[-exp(\frac{x - \mu}{\sigma})]。它如下图所示。

此外，我的 \begin{cases} .... \end{cases} 无法运行。这是我的代码：-

    \documentclass{beamer}

    \usepackage{amsmath}
    \usepackage{amssymb}
    \usepackage{comicsans}
    \usepackage{graphicx}
    \usepackage[inline]{enumitem}
    \usepackage{array}

    \makeatletter
    \newcommand*{\rom}[1]{\expandafter\@slowromancap\romannumeral #1@}
    \makeatother

    \begin{document}

   \begin{frame}
   \frametitle{1.2.1 Gumbel Distribution}

    \begin{itemize}
     \item a.k.a the Extreme Value Type  \rom{1} distribution is bounded and has the          
    following probability density function $$F(x)= exp [- exp(\frac{x-\mu}{\sigma})]$$     
    %repair this 
    where, \\
    $\mu$ is the location parameter,\\
    $\sigma$ is the scale parameter, ($\sigma$>0).\\
    \vspace{0.3cm}

    The shape of the Gumbel model does not depend on he distribution parameters.

     \end{itemize}
     \end{frame}

     \begin{frame}
     $$
     F(x) = \begin{cases}
     0, $ \text{$x>\mu$} \\
     exp[-{$\frac{x-\mu}{\sigma}}$], & $x \geq \mu$             
     \end{cases}
      $$ \\

     where \\
     $\xi$ is the shape parameter, \\
     $\mu$ is the location parameter, \\
     $\sigma$ is the scale parameter, ($\sigma$ > 0) [2]


     \end{frame}
     \end{document}

Answer 1

不美观，但可编译版本。可能将第一个&需要的\cases与$强制的临时更改混合在一起，并包含许多不需要的$。

\documentclass{beamer}

    \usepackage{amsmath}
    \usepackage{amssymb}
  % \usepackage{comicsans}
    \usepackage{graphicx}
 %  \usepackage[inline]{enumitem}
    \usepackage{array}

    \makeatletter
    \newcommand*{\rom}[1]{\expandafter\@slowromancap\romannumeral #1@}
    \makeatother

    \begin{document}

   \begin{frame}
   \frametitle{1.2.1 Gumbel Distribution}

    \begin{itemize}
     \item a.k.a the Extreme Value Type  \rom{1} distribution is bounded and has the          
    following probability density function 
\[
F(x)= \exp [- \exp(\frac{x-\mu}{\sigma})]
\]   
    %repair this 
    where, \\
    $\mu$ is the location parameter,\\
    $\sigma$ is the scale parameter, ($\sigma>0$).\\
    \vspace{0.3cm}

    The shape of the Gumbel model does not depend on he distribution parameters.

     \end{itemize}
     \end{frame}

     \begin{frame}
     \[
     F(x) = \begin{cases}
     0, &\text{$x>\mu$} \\
     exp[-{\frac{x-\mu}{\sigma}}], & x \geq \mu            
     \end{cases}
      \]
     where \\
     $\xi$ is the shape parameter, \\
     $\mu$ is the location parameter, \\
     $\sigma$ is the scale parameter, ($\sigma > 0$) [2]


     \end{frame}
     \end{document}