Here are some more complex uses of the MathJax notation, including chemistry, commutative diagrams, tooltips and more.

Mathematical Transformation

The solutions of $$ax^2 + by + c = 0$$ are given by \eqref{quad} below:

\begin{equation} x = \frac{ - b \pm \sqrt {b^2 - 4ac} }{2a} \label{quad} \end{equation}

Chemical Equation

Hey, check out my ability to do chemical equations and to reference them \eqref{eq:chem} inline.

\begin{equation} \ce{C6H5-CHO} \ce{$A$ ->[\ce{+H2O}] $B$} \ce{SO4^2- + Ba^2+ -> BaSO4 v} \label{eq:chem} \end{equation}

Tooltips

$$ \texttip{ \bbox[red]{x+y} }{Here is a non-math Tooltip} $$

$$ \mathtip{ \bbox[blue]{x+y} }{Here + is + a + math + Tooltip} $$

Commutative Diagrams

Boxes and Borders

$$ \bbox[5px,border:2px solid red]{x+y} $$

$$ \langle digit \rangle ::= $$