# Adding math to Jekyll themed (GitHub) website

All the (math) text that is between  tags will be displayed as a formula on a separate line, and the $tag is used for inline math. Then, in each post where you want to use math you need to add mathjax: true to the YAML header. This lets us use inline math such as$\int^b_a \int f(x,y)\,\mathrm{d}x\mathrm{d}y$, and math on a separate line: ${n+1\choose k} = {n\choose k} + {n \choose k-1}$. Note that contrary to regular latex practice, you want to avoid using a single  tag to result in inline math. The reason for this is that you might want to use the dollar sign  for prices without the text in between being parsed into math. For example the sentence Each apple costs 1 and a pear 2. would be parsed as: Each apple costs$1 and a pear @@2.