a post with math

This theme supports rendering beautiful math in inline and display modes using MathJax 3 engine. You just need to surround your math expression with $$, like $$ E = mc^2 $$. If you leave it inside a paragraph, it will produce an inline expression, just like $E=m{c}^2$.

To use display mode, again surround your expression with $$ and place it as a separate paragraph. Here is an example:

$$\sum _{k=1}^{\mathrm{\infty }}|⟨x,e_k⟩{|}^2\le \Vert x{\Vert }^2$$

You can also use \begin{equation}...\end{equation} instead of $$ for display mode math. MathJax will automatically number equations:

\begin{equation} \label{eq:cauchy-schwarz} \left( \sum{k=1}^n a_k b_k \right)^2 \leq \left( \sum{k=1}^n ak^2 \right) \left( \sum{k=1}^n b_k^2 \right) \end{equation}

and by adding \label{...} inside the equation environment, we can now refer to the equation using \eqref.

Note that MathJax 3 is a major re-write of MathJax that brought a significant improvement to the loading and rendering speed, which is now on par with KaTeX.