方程指数中的误差

Question

请帮忙解决方程的指数部分。出现错误。我正在使用 overleaf

\begin{equation}
   p(r)= (r/\upsilon^2)e^((r^2)/2\upsilon^2) ;  
   (0>=r>=\infty);
   p(r)= 0 ; (r<=0).
\end{equation}

Answer 1

\documentclass{article}

\usepackage{amsmath}
\usepackage{IEEEtrantools}

\begin{document}
OP's code after correcting the exponential and inequality symbols. 
\begin{equation}
   p(r)= (r/\upsilon^2)e^{((r^2)/2\upsilon^2)} ;  
   (0 \geq r \geq \infty);
   p(r)= 0 ; (r \leq 0).
\end{equation}

Multiple equations using \verb|IEEEeqnarray| environment.
\begin{IEEEeqnarray}{rCll}
   p(r) &=& (r/\upsilon^2)e^{((r^2)/2\upsilon^2)};  
   & \quad 0 \geq r \geq \infty; \\
   p(r) &=& 0; & \quad r \leq 0.
\end{IEEEeqnarray}

Using \verb|cases| environment.
\begin{equation}
    p(r) = 
    \begin{cases}
    (r/\upsilon^2)e^{((r^2)/2\upsilon^2)}; & 0 \geq r \geq \infty;; \\
    p(r)= 0; & r \leq 0.
    \end{cases}
\end{equation}
\end{document}