Typesetting Math with KaTeX

Math is a first-class citizen on this blog. Thanks to remark-math and rehype-katex, you can write LaTeX directly in Markdown and get properly typeset output.

Inline math

Wrap an expression in single dollar signs to render it inline, like $E = mc^2$ or the quadratic formula $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.

Display math

For a standalone equation, put $$ on its own line:

$$\int_{a}^{b} f(x)\,dx = F(b) - F(a)$$

The definition of the Gaussian integral is another classic:

$$\int_{-\infty}^{\infty} e^{-x^2}\,dx = \sqrt{\pi}$$

Matrices and summations

KaTeX handles more advanced notation too. Here is a matrix:

$$A = \begin{pmatrix} a_{11} & a_{12} \\ a_{21} & a_{22} \end{pmatrix}$$

And a summation with limits:

$$\sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6}$$

A note on escaping

Because $ is the delimiter, avoid using a lone dollar sign in prose unless you mean to open math. If you need a literal one, escape it as \$.

Math rendering happens at build time, so there is no client-side JavaScript cost — the HTML ships with the equations already typeset.

Comments