NoteDiscovery/documentation/MATHJAX.md

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🧮 LaTeX/MathJax Reference

NoteDiscovery supports LaTeX mathematical notation powered by MathJax 3. Write beautiful equations in your notes using familiar LaTeX syntax.

Syntax Overview

Delimiter Type Behavior
$...$ Inline Flows with text, not centered
\(...\) Inline Same as $...$ (LaTeX standard)
$$...$$ Display Own paragraph, centered, larger
\[...\] Display Same as $$...$$ (LaTeX standard)

Inline Math (within text)

Inline math flows with your text: $E = mc^2$ renders as E = mc^2

Display Math (centered, on its own line)

Display math gets its own centered paragraph:

$$
x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}
$$

Or using LaTeX-style delimiters:

\[
x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}
\]

x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}

Basic Examples

Superscripts and Subscripts

Superscripts use ^:

  • $x^2$x^2
  • $e^{i\pi}$e^{i\pi}

Subscripts use _:

  • $x_1$x_1
  • $a_{ij}$a_{ij}

Combined:

  • $x_1^2$x_1^2
  • $\sum_{i=1}^{n} i^2$\sum_{i=1}^{n} i^2

Fractions

Simple fractions: $\frac{a}{b}$\frac{a}{b}

Complex fractions:


\frac{\frac{1}{x}+\frac{1}{y}}{x+y} = \frac{x+y}{xy(x+y)} = \frac{1}{xy}

Square Roots

  • $\sqrt{2}$\sqrt{2}
  • $\sqrt[3]{8}$\sqrt[3]{8} (cube root)
  • $\sqrt{x^2 + y^2}$\sqrt{x^2 + y^2}

Greek Letters

Lowercase

$\alpha, \beta, \gamma, \delta, \epsilon, \zeta, \eta, \theta, \lambda, \mu, \pi, \sigma, \tau, \phi, \chi, \psi, \omega$

\alpha, \beta, \gamma, \delta, \epsilon, \zeta, \eta, \theta, \lambda, \mu, \pi, \sigma, \tau, \phi, \chi, \psi, \omega

Uppercase

$\Gamma, \Delta, \Theta, \Lambda, \Xi, \Pi, \Sigma, \Phi, \Psi, \Omega$

\Gamma, \Delta, \Theta, \Lambda, \Xi, \Pi, \Sigma, \Phi, \Psi, \Omega


Calculus

Integrals

Definite integral:

$$
\int_{0}^{\infty} e^{-x^2} dx = \frac{\sqrt{\pi}}{2}
$$

\int_{0}^{\infty} e^{-x^2} dx = \frac{\sqrt{\pi}}{2}

Multiple integrals:

$$
\iiint_V f(x,y,z) \, dx \, dy \, dz
$$

\iiint_V f(x,y,z) \, dx \, dy \, dz

Derivatives

First derivative: $\frac{df}{dx}$\frac{df}{dx}

Partial derivatives: $\frac{\partial f}{\partial x}$\frac{\partial f}{\partial x}

Gradient:

$$
\nabla f = \frac{\partial f}{\partial x}\mathbf{i} + \frac{\partial f}{\partial y}\mathbf{j} + \frac{\partial f}{\partial z}\mathbf{k}
$$

\nabla f = \frac{\partial f}{\partial x}\mathbf{i} + \frac{\partial f}{\partial y}\mathbf{j} + \frac{\partial f}{\partial z}\mathbf{k}

Limits

$$
\lim_{x \to \infty} \frac{1}{x} = 0
$$

\lim_{x \to \infty} \frac{1}{x} = 0

Summations and Products

Summation

Inline: \sum_{i=1}^{n} i = \frac{n(n+1)}{2}

Display:

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

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

Product

$$
\prod_{i=1}^{n} i = n!
$$

\prod_{i=1}^{n} i = n!

Matrices and Vectors

Basic Matrix

$$
\begin{bmatrix}
a & b \\\ 
c & d
\end{bmatrix}
$$

\begin{bmatrix}
a & b \\\ 
c & d
\end{bmatrix}

Larger Matrix

$$
A = \begin{bmatrix}
1 & 2 & 3 \\\ 
4 & 5 & 6 \\\ 
7 & 8 & 9
\end{bmatrix}
$$

A = \begin{bmatrix}
1 & 2 & 3 \\\ 
4 & 5 & 6 \\\ 
7 & 8 & 9
\end{bmatrix}

Identity Matrix

$$
I = \begin{pmatrix}
1 & 0 & 0 \\\ 
0 & 1 & 0 \\\ 
0 & 0 & 1
\end{pmatrix}
$$

I = \begin{pmatrix}
1 & 0 & 0 \\\ 
0 & 1 & 0 \\\ 
0 & 0 & 1
\end{pmatrix}

Determinant

$$
\det(A) = \begin{vmatrix}
a & b \\\ 
c & d
\end{vmatrix} = ad - bc
$$

\det(A) = \begin{vmatrix}
a & b \\\ 
c & d
\end{vmatrix} = ad - bc

Advanced Features

Systems of Equations

$$
\begin{cases}
x + y = 5 \\\ 
2x - y = 1
\end{cases}
$$

\begin{cases}
x + y = 5 \\\ 
2x - y = 1
\end{cases}

Aligned Equations

$$
\begin{aligned}
f(x) &= (x+1)^2 \\\ 
&= x^2 + 2x + 1
\end{aligned}
$$

\begin{aligned}
f(x) &= (x+1)^2 \\\ 
&= x^2 + 2x + 1
\end{aligned}

Continued Fractions

$$
\phi = 1 + \frac{1}{1 + \frac{1}{1 + \frac{1}{1 + \cdots}}}
$$

\phi = 1 + \frac{1}{1 + \frac{1}{1 + \frac{1}{1 + \cdots}}}

Mathematical Symbols

Operators

Symbol LaTeX Result
Plus-minus $\pm$ \pm
Multiply $\times$ \times
Divide $\div$ \div
Not equal $\neq$ \neq
Less/Greater $\leq, \geq$ \leq, \geq
Approx $\approx$ \approx
Infinity $\infty$ \infty

Set Theory

Symbol LaTeX Result
Element of $\in$ \in
Not element $\notin$ \notin
Subset $\subset$ \subset
Union $\cup$ \cup
Intersection $\cap$ \cap
Empty set $\emptyset$ \emptyset

Logic

Symbol LaTeX Result
And $\land$ \land
Or $\lor$ \lor
Not $\neg$ \neg
Implies $\implies$ \implies
If and only if $\iff$ \iff
For all $\forall$ \forall
Exists $\exists$ \exists

Famous Equations

Euler's Identity

 e^{i\pi} + 1 = 0 

Einstein's Mass-Energy Equivalence

 E = mc^2 

Pythagorean Theorem

 a^2 + b^2 = c^2 

Schrödinger Equation

 i\hbar\frac{\partial}{\partial t}\Psi(\mathbf{r},t) = \hat{H}\Psi(\mathbf{r},t) 

Maxwell's Equations

$$
\begin{aligned}
\nabla \cdot \mathbf{E} &= \frac{\rho}{\epsilon_0} \\\ 
\nabla \cdot \mathbf{B} &= 0 \\\ 
\nabla \times \mathbf{E} &= -\frac{\partial \mathbf{B}}{\partial t} \\\ 
\nabla \times \mathbf{B} &= \mu_0\mathbf{J} + \mu_0\epsilon_0\frac{\partial \mathbf{E}}{\partial t}
\end{aligned}
$$

\begin{aligned}
\nabla \cdot \mathbf{E} &= \frac{\rho}{\epsilon_0} \\\ 
\nabla \cdot \mathbf{B} &= 0 \\\ 
\nabla \times \mathbf{E} &= -\frac{\partial \mathbf{B}}{\partial t} \\\ 
\nabla \times \mathbf{B} &= \mu_0\mathbf{J} + \mu_0\epsilon_0\frac{\partial \mathbf{E}}{\partial t}
\end{aligned}

Tips

1. Preview Mode

Always use Split View or Preview Mode to see your equations rendered in real-time.

2. Escaping Dollar Signs

If you need a literal dollar sign (not math), escape it: $\\$100$ renders as \\$100

3. Complex Expressions

For very long equations, consider breaking them across multiple lines using aligned or split environments.

4. Matrix & Multi-line Formatting

IMPORTANT: Use 3 backslashes + space (\\\ ) for line breaks to enable multi-line formatting:

✅ Good (readable multi-line format):
$$
\begin{bmatrix}
a & b \\\ 
c & d
\end{bmatrix}
$$

❌ Bad (only 2 backslashes - won't work):
$$
\begin{bmatrix}
a & b \\
c & d
\end{bmatrix}
$$

The Secret: Use \\\ (three backslashes + trailing space) at the end of each row, then add a newline. This allows for readable multi-line equations!

5. Debugging

If an equation doesn't render:

  • Check for matching delimiters ($...$ or $$...$$)
  • Ensure backslashes are correct (\frac not /frac)
  • Look for unescaped special characters
  • For matrices/line breaks, use \\\ (three backslashes + space) not \\
  • Make sure there's a trailing space after \\\ before the newline

6. Performance

MathJax renders efficiently, but very equation-heavy notes (100+ equations) may take a moment to typeset.


Resources

For more LaTeX commands and symbols, see:


💡 Tip: Copy and paste examples from this note to quickly start using math in your own notes!