Mathematical Symbols

1. Basic Arithmetic Operators

Symbol Meaning Example
\(+\) Addition \(2 + 3 = 5\)
\(-\) Subtraction \(7 - 4 = 3\)
\(\times\) Multiplication \(2 \times 3 = 6\)
\(\div\) Division \(6 \div 2 = 3\)
\(\%\) Percentage \(25\% \text{ of } 80 = 20\)

2. Comparison Symbols

Symbol Meaning Example
\(=\) Equal to \(5 = 5\)
\(\neq\) Not equal to \(4 \neq 5\)
\(<\) Less than \(3 < 5\)
\(>\) Greater than \(7 > 5\)
\(\leq\) Less than or equal to \(3 \leq 3\)
\(\geq\) Greater than or equal to \(5 \geq 5\)
\(\approx\) Approximately equal to \(\pi \approx 3.14\)
\(\equiv\) Identical to \(x \equiv x\)
\(\sim\) Similar to \(\triangle ABC \sim \triangle DEF\)
\(\propto\) Proportional to \(y \propto x\)

3. Set Theory Symbols

Symbol Meaning Example
\(\in\) Element of \(2 \in \mathbb{Z}\)
\(\notin\) Not an element of \(\pi \notin \mathbb{Q}\)
\(\ni\) Contains as an element \(\mathbb{R} \ni \pi\)
\(\subset\) Proper subset \(\{1,2\} \subset \{1,2,3\}\)
\(\subseteq\) Subset \(\{1,2\} \subseteq \{1,2,3\}\)
\(\supset\) Proper superset \(\{1,2,3\} \supset \{1,2\}\)
\(\supseteq\) Superset \(\{1,2,3\} \supseteq \{1,2\}\)
\(\cup\) Union \(A \cup B\)
\(\cap\) Intersection \(A \cap B\)
\(\setminus\) Set difference \(A \setminus B\)
\(\emptyset\) Empty set \(\{x \in \mathbb{N} : x < 0\} = \emptyset\)

4. Logic Symbols

Symbol Meaning Example
\(\wedge\) And \(p \wedge q\)
\(\vee\) Or \(p \vee q\)
\(\neg\) Not \(\neg p\)
\(\Rightarrow\) Implies \(p \Rightarrow q\)
\(\Leftrightarrow\) If and only if \(p \Leftrightarrow q\)
\(\forall\) For all \(\forall x \in \mathbb{R}\)
\(\exists\) There exists \(\exists x \in \mathbb{R}\)
\(\therefore\) Therefore \(A=B, B=C, \therefore A=C\)
\(\because\) Because \(\because A=B \text{ and } B=C, \therefore A=C\)

5. Geometry Symbols

Symbol Meaning Example
\(\angle\) Angle \(\angle ABC\)
\(\perp\) Perpendicular \(l_1 \perp l_2\)
\(\parallel\) Parallel \(l_1 \parallel l_2\)
\(\cong\) Congruent \(\triangle ABC \cong \triangle DEF\)
\(\sim\) Similar \(\triangle ABC \sim \triangle DEF\)
\(\triangle\) Triangle \(\triangle ABC\)
\(\square\) Square \(\square ABCD\)
\(\circ\) Degree \(90^\circ\)
\(\pi\) Pi \(\pi r^2\)

6. Calculus Symbols

Symbol Meaning Example
\(\int\) Integral \(\int_a^b f(x) dx\)
\(\oint\) Contour integral \(\oint_C f(z) dz\)
\(\partial\) Partial derivative \(\frac{\partial f}{\partial x}\)
\(\nabla\) Gradient \(\nabla f\)
\(\lim\) Limit \(\lim_{x \to \infty} f(x)\)
\(\sum\) Summation \(\sum_{i=1}^n i\)
\(\prod\) Product \(\prod_{i=1}^n i\)
\(\frac{d}{dx}\) Derivative \(\frac{d}{dx} f(x)\)
\(\iint\) Double integral \(\iint_D f(x, y) dx dy\)

7. Algebra Symbols

Symbol Meaning Example
\(\sqrt{}\) Square root \(\sqrt{4} = 2\)
\(\sqrt[n]{}\) nth root \(\sqrt[3]{8} = 2\)
\(\|x\|\) Absolute value \(\|-5\| = 5\)
\(n!\) Factorial \(5! = 120\)
\(\binom{n}{k}\) Binomial coefficient \(\binom{5}{2} = 10\)
\(\oplus\) Exclusive or \(1 \oplus 1 = 0\)
\(\otimes\) Kronecker product \(A \otimes B\)

8. Number Theory Symbols

Symbol Meaning Example
\(\mid\) Divides \(3 \mid 9\)
\(\nmid\) Does not divide \(3 \nmid 10\)
\(\pmod{}\) Modulo operation \(7 \pmod{3} \equiv 1\)
\(\gcd\) Greatest common divisor \(\gcd(12,18) = 6\)
\(\text{lcm}\) Least common multiple \(\text{lcm}(4,6) = 12\)
\(\infty\) Infinity \(\lim_{x \to 0} \frac{1}{x} = \infty\)

9. Matrix and Linear Algebra Symbols

Symbol Meaning Example
\(\det\) Determinant \(\det(A)\)
\(\text{tr}\) Trace of a matrix \(\text{tr}(A)\)
\(A^T\) Matrix transpose \((A^T)_{ij} = A_{ji}\)
\(A^{-1}\) Matrix inverse \(AA^{-1} = I\)
\(\ker\) Kernel \(\ker(T)\)
\(\text{Im}\) Image \(\text{Im}(T)\)
\(\text{rank}\) Rank \(\text{rank}(A)\)
\(\dim\) Dimension \(\dim(V)\)
\(\text{span}\) Span \(\text{span}\{v_1, v_2, \ldots, v_n\}\)
\(\cdot\) Dot product \(\mathbf{a} \cdot \mathbf{b} = a_1 b_1 + a_2 b_2 + a_3 b_3\)
\(\times\) Cross product \(\mathbf{a} \times \mathbf{b} = (a_2 b_3 - a_3 b_2, a_3 b_1 - a_1 b_3, a_1 b_2 - a_2 b_1)\)
\(\otimes\) Kronecker product \(A \otimes B\)
\(\mathbf{0}\) Zero vector \(\mathbf{0} = (0, 0, \ldots, 0)\)

10. Complex Number Symbols

Symbol Meaning Example
\(i\) Imaginary unit \(i^2 = -1\)
\(z^*\) Complex conjugate \((a+bi)^* = a-bi\)
\(\|z\|\) Modulus \(\|3+4i\| = 5\)
\(\arg(z)\) Argument \(\arg(1+i) = \frac{\pi}{4}\)

11. Statistics Symbols

Symbol Meaning Example
\(\mu\) Population mean \(\mu = \frac{1}{N}\sum_{i=1}^N x_i\)
\(\sigma\) Standard deviation \(\sigma = \sqrt{\frac{1}{N}\sum_{i=1}^N (x_i - \mu)^2}\)
\(\sigma^2\) Variance \(\sigma^2 = \frac{1}{N}\sum_{i=1}^N (x_i - \mu)^2\)
\(\rho\) Correlation coefficient \(-1 \leq \rho \leq 1\)
\(\chi^2\) Chi-squared \(\chi^2 = \sum \frac{(O-E)^2}{E}\)

12. Special Constants

Symbol Meaning Example
\(e\) Euler's number \(\lim_{n \to \infty} \left(1 + \frac{1}{n}\right)^n = e\)
\(\pi\) Pi \(\pi \approx 3.14159\)
\(i\) Imaginary unit \(i^2 = -1\)
\(\gamma\) Euler-Mascheroni constant \(\gamma \approx 0.57721\)
\(\phi\) Golden ratio \(\phi = \frac{1 + \sqrt{5}}{2} \approx 1.618\)
\(\zeta(3)\) Apéry's constant \(\zeta(3) = \sum_{n=1}^{\infty} \frac{1}{n^3} \approx 1.20206\)
\(\ln(2)\) Natural logarithm of 2 \(\ln(2) \approx 0.69315\)
\(\delta\) Khinchin's constant \(\delta \approx 2.68545\)
\(\lambda\) Lemniscate constant \(\lambda \approx 2.62205\)
\(K\) Catalan's constant \(K \approx 0.91596\)
\(M\) Meissel-Mertens constant \(M \approx 0.261497\)

13. Other Symbols

Symbol Meaning Example
\(\nabla\) Gradient, divergence, or curl \(\nabla f\)
\(\Box\) End of proof \(\therefore x = 2 \quad \Box\)
\(\sim\) Distributed as \(X \sim N(\mu, \sigma^2)\)
\(\asymp\) Asymptotically equivalent \(f(x) \asymp g(x)\)
\(\ll\) Much less than \(1 \ll 1000\)
\(\gg\) Much greater than \(1000 \gg 1\)
\(\to\) Tends to \(x \to \infty\)
\(\mapsto\) Maps to \(f: x \mapsto x^2\)

Greek Alphabet

Symbol (Lowercase) Symbol (Uppercase) Pronunciation Meaning Example
\(\alpha\) \(A\) Alpha Angle, coefficient \(\alpha = 45^\circ\)
\(\beta\) \(B\) Beta Angle, coefficient \(\beta = 0.5\)
\(\gamma\) \(\Gamma\) Gamma Gamma function \(\Gamma(x)\)
\(\delta\) \(\Delta\) Delta Delta function, change \(\Delta x = x_2 - x_1\)
\(\epsilon\) \(E\) Epsilon Small quantity, permittivity \(\epsilon > 0\)
\(\zeta\) \(Z\) Zeta Zeta function \(\zeta(s)\)
\(\eta\) \(H\) Eta Efficiency, viscosity \(\eta = 0.8\)
\(\theta\) \(\Theta\) Theta Angle \(\theta = 30^\circ\)
\(\iota\) \(\iota\) Iota Small quantity, index \(\iota_n\)
\(\kappa\) \(K\) Kappa Curvature \(\kappa = \frac{1}{R}\)
\(\lambda\) \(\Lambda\) Lambda Eigenvalue, wavelength \(\lambda = 500 \, \text{nm}\)
\(\mu\) \(M\) Mu Mean, magnetic moment \(\mu = 10\)
\(\nu\) \(N\) Nu Frequency \(\nu = 60 \, \text{Hz}\)
\(\xi\) \(\Xi\) Xi Random variable \(\xi \sim N(0, 1)\)
\(o\) \(O\) Omicron Omicron \(o(n)\)
\(\pi\) \(\Pi\) Pi Pi, product \(\pi \approx 3.14\)
\(\rho\) \(P\) Rho Density, resistivity \(\rho = 1000 \, \text{kg/m}^3\)
\(\sigma\) \(\Sigma\) Sigma Standard deviation, sum \(\sigma = 2\)
\(\tau\) \(T\) Tau Tau, torque \(\tau = 5 \, \text{Nm}\)
\(\upsilon\) \(\Upsilon\) Upsilon Upsilon \(\Upsilon(x)\)
\(\phi\) \(\Phi\) Phi Phi, potential \(\phi = 10 \, \text{V}\)
\(\chi\) \(X\) Chi Chi, chi-squared \(\chi^2\)
\(\psi\) \(\Psi\) Psi Psi, wave function \(\Psi(x, t)\)
\(\omega\) \(\Omega\) Omega Omega, angular frequency \(\omega = 2\pi f\)