数学标记及其英文读法

2025-06-08
学习积累
Symbol         Pronunciation                 Example Example Reading    
$\pi$ pi $\pi \approx 3.14$ pi approximately 3 point 14
$\hat{x}$ x hat $\hat{x} = 5$ x hat equals 5
$x^2$ x squared $x^2 + y^2 = z^2$ x squared plus y squared equals z squared
$x_n$ x sub n $x_n = \frac{1}{n}$ x sub n equals one over n
$\sum$ summation $\sum_{i=1}^n i$ summation from i equals 1 to n of i
$\int$ integral $\int_0^1 x,dx$ integral from 0 to 1 of x dx
$\infty$ infinity $\lim_{x \to \infty} f(x)$ limit as x approaches infinity of f of x
$\lim$ limit $\lim_{x \to 0} \frac{\sin x}{x}$ limit as x approaches 0 of sin x over x
$\forall$ for all $\forall x \in \mathbb{R}$ for all x in real numbers
$\exists$ there exists $\exists x > 0$ there exists x greater than zero
$\equiv$ is congruent to $a \equiv b \pmod{n}$ a is congruent to b modulo n
$\to$ approaches / tends to $x \to 0$ x approaches zero
$\approx$ approximately equals $\pi \approx 3.14$ pi approximately equals 3 point 14
$\nabla$ del / gradient $\nabla f(x,y)$ gradient of f at x y
$\cdot$ dot $a \cdot b$ a dot b
$\times$ times / cross $\vec{a} \times \vec{b}$ vector a cross vector b
$\Rightarrow$ implies $P \Rightarrow Q$ P implies Q
$\leftarrow$ left arrow $x \leftarrow y$ x left arrow y
$\neq$ not equal $x \neq y$ x not equal y
$\leq$ less than or equal to $x \leq y$ x less than or equal to y
$\geq$ greater than or equal to $x \geq y$ x greater than or equal to y
$\subset$ is subset of $A \subset B$ A is subset of B
$\supset$ is superset of $B \supset A$ B is superset of A
$\cup$ union $A \cup B$ A union B
$\cap$ intersection $A \cap B$ A intersection B
$\mathbb{R}$ real numbers $\mathbb{R}$ real numbers
$\mathbb{N}$ natural numbers $\mathbb{N}$ natural numbers
$\partial$ partial (derivative) $\frac{\partial f}{\partial x}$ partial derivative of f with respect to x