Math Equations
Write beautiful mathematical equations using LaTeX/KaTeX notation in MD Editor.
Overview
MD Editor uses KaTeX for fast, high-quality mathematical rendering. You can write inline equations and display (block) equations using LaTeX syntax.
Inline Math
Use single dollar signs for inline equations within text.
Example syntax:
The Pythagorean theorem is $a^2 + b^2 = c^2$.Display Math
Use double dollar signs for display equations (centered on their own line).
Example syntax:
$$
\int_{-\infty}^{\infty} e^{-x^2} dx = \sqrt{\pi}
$$Common Mathematical Notation
Superscripts and Subscripts
$x^2$, $x^{10}$, $x_1$, $x_{ij}$Fractions
$\frac{1}{2}$, $\frac{a + b}{c + d}$Square Roots
$\sqrt{2}$, $\sqrt[3]{8}$, $\sqrt{x^2 + y^2}$Greek Letters
$\alpha$, $\beta$, $\gamma$, $\Delta$, $\pi$, $\Sigma$, $\Omega$Operators
$\sum_{i=1}^{n} x_i$, $\prod_{i=1}^{n} x_i$, $\lim_{x \to \infty} f(x)$Complex Equations
Quadratic Formula
$$
x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
$$Matrix
$$
\begin{bmatrix}
a & b \\
c & d
\end{bmatrix}
$$System of Equations
$$
\begin{cases}
x + y = 5 \\
x - y = 1
\end{cases}
$$Integral
$$
\int_0^1 x^2 \, dx = \frac{1}{3}
$$Summation
$$
\sum_{k=1}^{n} k = \frac{n(n+1)}{2}
$$Advanced Features
Aligned Equations
$$
\begin{aligned}
f(x) &= x^2 + 2x + 1 \\
&= (x + 1)^2
\end{aligned}
$$Multi-line Equations
$$
\begin{gather}
a = b + c \\
d = e + f + g \\
h = i + j + k + l
\end{gather}
$$Matrices with Different Brackets
Parentheses:
$\begin{pmatrix} a & b \\ c & d \end{pmatrix}$Brackets:
$\begin{bmatrix} a & b \\ c & d \end{bmatrix}$Braces:
$\begin{Bmatrix} a & b \\ c & d \end{Bmatrix}$Vertical bars:
$\begin{vmatrix} a & b \\ c & d \end{vmatrix}$Mathematical Symbols
Comparison Operators
$<$, $>$, $\leq$, $\geq$, $\neq$, $\approx$, $\equiv$Set Notation
$\in$, $\notin$, $\subset$, $\subseteq$, $\cup$, $\cap$, $\emptyset$Logic Symbols
$\land$, $\lor$, $\neg$, $\implies$, $\iff$, $\forall$, $\exists$Arrows
$\rightarrow$, $\leftarrow$, $\Rightarrow$, $\Leftarrow$, $\leftrightarrow$, $\Leftrightarrow$Text in Math Mode
Use the text command for text within equations:
$$
P(\text{success}) = \frac{\text{favorable outcomes}}{\text{total outcomes}}
$$Spacing in Math
Control spacing with these commands:
- Thin space:
\, - Medium space:
\: - Thick space:
\; - Quad space:
\quad - Double quad space:
\qquad
Example:
$a\,b$, $a\:b$, $a\;b$, $a\quad b$, $a\qquad b$Special Functions
$\sin(x)$, $\cos(x)$, $\tan(x)$, $\log(x)$, $\ln(x)$, $\exp(x)$Accents and Decorations
$\hat{x}$, $\bar{x}$, $\tilde{x}$, $\vec{x}$, $\dot{x}$, $\ddot{x}$Large Operators
$$
\sum_{i=1}^{n} \quad \prod_{i=1}^{n} \quad \int_{a}^{b} \quad \oint_{C} \quad \bigcup_{i=1}^{n} \quad \bigcap_{i=1}^{n}
$$Tips for Writing Math
- Use display mode for important equations - Makes them stand out
- Keep inline math simple - Complex expressions work better in display mode
- Use proper notation - Follow mathematical conventions
- Add context - Explain variables and symbols
- Test rendering - Preview your equations as you write
Common Pitfalls
Escaping Special Characters
If you need to use literal dollar signs in text, escape them with a backslash.
Example: The price is \$100
Curly Braces
Use backslash-escaped braces for literal braces in math.
Example: $\{x : x > 0\}$
KaTeX Support
MD Editor uses KaTeX for fast math rendering. Most LaTeX math commands are supported. For a complete reference, see the KaTeX documentation (opens in a new tab).
Examples from Different Fields
Physics - Newton's Law of Universal Gravitation
$$
F = G\frac{m_1 m_2}{r^2}
$$Statistics - Standard Deviation
$$
\sigma = \sqrt{\frac{1}{N}\sum_{i=1}^{N}(x_i - \mu)^2}
$$Calculus - Fundamental Theorem of Calculus
$$
\frac{d}{dx}\left[\int_{a}^{x} f(t)\,dt\right] = f(x)
$$Quick Reference
Common LaTeX commands for math:
- Superscript:
^ - Subscript:
_ - Fraction:
\frac{numerator}{denominator} - Square root:
\sqrt{x}or\sqrt[n]{x} - Sum:
\sum_{lower}^{upper} - Integral:
\int_{lower}^{upper} - Product:
\prod_{lower}^{upper} - Limit:
\lim_{x \to value} - Partial derivative:
\frac{\partial f}{\partial x} - Infinity:
\infty - Greek letters:
\alpha,\beta,\gamma, etc.