How to Enable It
Add math: true to your front matter. That’s it. Spectra will load KaTeX automatically — no extra setup needed.
Inline Formulas
Wrap a formula in two $ signs and it shows up right in the middle of your text.
For example, Euler’s identity $e^{i\pi} + 1 = 0$ is often called the most beautiful equation in math. And $E = mc^2$ is probably the most famous physics formula out there.
Inline formulas don’t line-break, so if yours is getting long, use block format instead.
Block Formulas
Wrap a formula in $$ and it gets its own line, centered.
The Gaussian integral:
$$\int_{-\infty}^{\infty} e^{-x^2}\, dx = \sqrt{\pi}$$This result is pretty wild — an integral involving $e$ and the answer has $\pi$ in it.
Common Formula Examples
Bayes’ Theorem
You can’t escape this one in statistics or machine learning:
$$P(A \mid B) = \frac{P(B \mid A)\, P(A)}{P(B)}$$In plain terms: how you should update your belief about something after seeing new evidence.
Quadratic Formula
You learned this one in school, but it looks extra official in LaTeX:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$Matrices
Matrix multiplication:
$$\begin{pmatrix} a & b \\ c & d \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} ax + by \\ cx + dy \end{pmatrix}$$Sums and Products
Sum of squares of natural numbers:
$$\sum_{k=1}^{n} k^2 = \frac{n(n+1)(2n+1)}{6}$$Factorial as a product:
$$n! = \prod_{k=1}^{n} k$$Limits
Where calculus begins:
$$f'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}$$Mixing It Up
Formulas blend naturally with regular text.
Say you have a dataset $x_1, x_2, \ldots, x_n$. Its mean is:
$$\bar{x} = \frac{1}{n} \sum_{i=1}^{n} x_i$$And the standard deviation:
$$\sigma = \sqrt{\frac{1}{n} \sum_{i=1}^{n} (x_i - \bar{x})^2}$$These two numbers basically tell you “where the data clusters” and “how spread out it is.”
Aligning Multi-line Formulas
Use the aligned environment to line up the equals signs:
