I've set up the TeX filter and am trying to use the expression on http://demo.moodle.org/mod/resource/view.php?id=11
However when I use texdebug it comes out like this:
It is missing the large integral symbol and sum symbol. Is there some additional configuration I need to add to the TeX preamble to get those symbols to work?
Works ok on my test server and PC without any additional configuration. Do you have any other filters on? Is your moodle using some custom tex files or files of moodle?
Normal \sum works perfectly fine, using \Bigsum gives:
! Undefined control sequence. l.8 $ \biggl[\Bigsum _i a_i\Bigl\lvert\sum_j x
MimeTeX binary is included to all current versions of moodle and MimeTeX has both Bigint and Bigsum... you could check that you have all core files of folder filter/tex installed and moodle can read and execute mimetex.