title: How to load desired Latex package in Rmarkdown?
body: <p>I want to use multirow option in Rstudio to create a latex pdf document in Rmarkdown , but for \multirow to work we need package multirow. How do i load the latex package multirow in the Rmarkdown??<br>
  I tried putting codes as follows:</p>
  
  <pre><code>---
  output:
    pdf_document: 
    header-includes: 
    - \usepackage{multirow}
    html_notebook: default
  ---
  </code></pre>
  
  <p>But it gives an error while knitting:</p>
  
  <pre><code>! Undefined control sequence. &lt;recently read&gt; \multirow
  </code></pre>
  
  <p>Please help me.. Thank you in advance</p>