My equation doesn't show the symbols: integral, equal, parentheses and etc.. These are the packages I've used and my latex code. Process exited normally. In log, no error messages related to equation, except for "bad box".Any idea on solving this? Thank you.
\usepackage{newtxtext,newtxmath}
\usepackage{txfonts}
\usepackage{mathtools}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{equation} \label{den_abel}
n_{e} (r) =\frac{\lambda n_{c}}{\pi^{2}}\int_{r}^{r_0}
\frac{\mathit{\phi(x)}}{dx} \frac{1}{\sqrt{x^{2}-r^{2}}}dx.
\end{equation}`
tested with
foo $\int(aba)$ bar
output:
Process exited normally. Log screenshot:

[SOLVED]
\documentclass{jjap3}
%\usepackage{newtxtext,newtxmath}
\usepackage{txfonts}
\usepackage{mathtools}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
\begin{equation} \label{den_abel}
n_{e} (r) =\frac{\lambda n_{c}}{\pi^{2}}\int_{r}^{r_0}
\frac{\mathit{\phi(x)}}{dx} \frac{1}{\sqrt{x^{2}-r^{2}}}dx.
\end{equation}
\end{document}
Thank you all for your comments:)





foo$\int(aba)$ bar– Aug 02 '18 at 06:51amsmathis loaded bymathtoolsalready – faltfe Aug 02 '18 at 06:55