我有这个可以运行的rmarkdown文档：
它在屏幕上生成一个html文档和
$$ \frac{\mbox{dsfa sdaf lj dsfl}}{dsf} $$
正确显示但是当单击关闭弹出的html文档并打开保存到上面代码的文件夹中的.html文档时，它不会转换为数学符号系统。 Inistead仍然是：$$ \ frac {\ mbox {dsfa sdaf lj dsfl}} {dsf} $$
如何在保存的html文档中翻译$$ \ frac {\ mbox {dsfa sdaf lj dsfl}} {dsf} $$？
谢谢
以下是代码：
---
title: "Untitled"
output:
html_document:
keep_md: true
header-includes:
- \usepackage{color}
- \usepackage{amsmath}
fig.lp: ('';character)
fig.pos: "H"
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE , comment = NA, message= FALSE, warning = FALSE)
```
## R Markdown
This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.
When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:
```{r cars}
summary(cars)
```
## Including Plots
You can also embed plots, for example:
```{r pressure, echo=FALSE}
plot(pressure)
```
Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
$$ \frac{\mbox{dsfa sdaf lj dsfl}}{dsf} $$