Knitr markdown can't display basic symbols

I'm on Ubuntu 14.04, running RStudio Version 0.99.473. I have LaTeX installed (TeXworks) and knitting Rmarkdown documents works just fine. However, adding mathematical symbols such as $\mu$ causes it to fail, with the error:

! Undefined control sequence.
l.128 N(\(\mu, \simga

pandoc: Error producing PDF from TeX source
Error: pandoc document conversion failed with error 43
Execution halted


(in my .Rmd file, I have $\mu, \sigma^2$ - it works if I remove the $'s and the slashes) In my experience, the LaTeX package amssymb has a lot of math symbols. tlmgr install amssymb doesn't work, so I'm lost. tlmgr install amssymb (running on Debian, switching to user mode!) tlmgr: The TeX Live versions supported by the repository http://tlcontrib.metatex.org/2012 (2011--2012) do not include the version of the local installation (2013).  (I don't actually know what that error means. Can it find some files but not the right ones? Do I need a different repository? How do I find different repositories?) How do I get $\mu$ to show up? I'm going to need to have more complicated equations, so it would be really nice to get basic math working. I should also mention that I have no idea where/how RStudio looks for LaTeX packages. I'm a Linux noob, but it's my only OS right now. Sorry if this isn't relevant to this forum, but this seemed like the right place to post it. • The macro \simga is undefined. Try with \sigma... – Paul Gaborit Mar 19 '16 at 8:49 1 Answer You won't be able to get anywhere without the amssymb and amsmath packages. It looks as if you're running TeX Live 2013; updating to 2015 will make you much happier. Knitr uses Pandoc to convert Markdown to LaTeX. Creating a file containing $\mu, \sigma^2\$ works fine with Pandoc 1.15.1.1 and TeX Live 2015.

• I actually have no idea how to do that. What do you mean "create a file"? What extension? Where do I put it? What actually goes in the file? How do I update TeX Live? (I tried tlmgr update -self' and sudo apt-get update texworks`, but neither did anything. I also tried reinstalling both TeXLive and TeXWorks from Ubuntu Software Center.) I'm really not that knowledgeable here, I just want some basic math symbols :( – D7Becker Oct 21 '15 at 2:01
• The TeX Live manager can only update within a single year; you need to download the complete 2015 distribution as appropriate for your system. – Andrew Dunning Oct 21 '15 at 13:21