求和的公式表达

内嵌公式，使用 $...$ . 单独展示的一行使用 $$...$$.
渲染的差别，比如
$\sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6}$
会显示 $\sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6}$ (内嵌模式) ，而下面这样
$\sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6}$
为独立的一块渲染区域，它是居中展示的，字体也要更大一些

符号

希腊字母,
\alpha, \beta, …, \omega: $\alpha, \beta, … \omega$ .

大写,
\Gamma, \Delta, …, \Omega: $\Gamma, \Delta, …, \Omega$ .

上标和下标,
use ^ and _. For example, x_i^2: $x_i^2$ , \log_2 x: $\log_2 x$ .

分组
Superscripts, subscripts, and other operations apply only to the next “group”. A “group” is either a single symbol, or any formula surrounded by curly braces {…}.
If you do 10^10, you will get a surprise: $10^10$ .
But 10^{10} gives what you probably wanted: $10^{10}$ .
Use curly braces to delimit a formula to which a superscript or subscript applies: x⁵6 is an error;
{x^y}z is ${x^y}^z$ , and x^{yz} is $x^{y^z}$ . Observe the difference between x_i^2 $x_i^2$ and x_{i^2} $x_{i^2}$ .

Parentheses(圆括号)
一般的()[]， $(2+3)[4+4]$ . Use \{ and \} for curly braces $\{\}$ .

These do not scale with the formula in between, so if you write (\frac{\sqrt x}{y^3}) the parentheses will be too small: (x√y3)

. Using \left(…\right) will make the sizes adjust automatically to the formula they enclose: $\left(\frac{\sqrt x}{y^3}\right)$ .

\left and \right apply to all the following sorts of parentheses:

synbol	means
`( and )`	$\left( x \right)$
`[ and ]`	$\left[ x \right]$
`\{ and \}`	$\left\{ x \right\}$
`\|`	$\left\| x \right\|$
`\vert , \Vert`	$\|x\|$ 有问题，可能需要在其他的语境下才生效
`\langle and \rangle`	$\langle x \rangle$
`\lceil and \rceil`	$\lceil x \rceil$
`\lfloor and \rfloor`	$\lfloor x \rfloor$

. \middle can be used to add additional dividers. There are also invisible parentheses, denoted by . :
\left. \frac12\right\rbrace is $\left.\frac12\right\rbrace$ .

If manual size adjustments are required: \Biggl(\biggl(\Bigl(\bigl((x)\bigr)\Bigr)\biggr)\Biggr) gives $\Biggl(\biggl(\Bigl(\bigl((x)\bigr)\Bigr)\biggr)\Biggr)$ .
Sums and integrals \sum and \int; the subscript is the lower limit and the superscript is the upper limit, so for example \sum_1^n $\sum_1^n$ . Don't forget {…} if the limits are more than a single symbol.
For example, \sum_{i=0}^\infty i^2 is
$\sum_{i=0}^\infty i^2$ .
Similarly,

symbol	redered as
`\prod`	$\prod$
`\int`	$\int$
`\bigcup`	$\bigcup$
`\bigcap`	$\bigcap$
`\iint`	$\iint$
`\iiint`	$\iiint$
`\idotsint`	$\idotsint$

Fractions There are three ways to make these. \frac ab applies to the next two groups, and produces $\frac ab$ ;
for more complicated numerators and denominators use {…}: \frac{a+1}{b+1} is $\frac{a+1}{b+1}$ .
If the numerator and denominator are complicated, you may prefer \over, which splits up the group that it is in: {a+1\over b+1} is ${a+1\over b+1}$ .
Using \cfrac{a}{b} command is useful for continued fractions $\cfrac{a}{b}$ , more details for which are given in this sub-article.

Fonts
Use \mathbb or \Bbb for "blackboard bold": ℂℍℕℚℝℤ

symbols	for	redered as
`\mathbb or \Bbb`	blackboard bold	$\Bbb AB \Bbb CD$
`\mathbf`	boldface	$\mathbf A BCDE$
`\mathit`	italics	$\mathit ABCDEFGHIJ$ , $\mathit abcdefgh$
`\pmb`	boldfaced italics	$\pmb ABCDEFG$ $\pmb abcdefghijk$
`\mathtt`	typewriter	$\mathtt ABCDEFGHIJK$
`\mathrm`	roman	$\mathrm abcvwxyz$
`\mathsf`	sans-serif	$\mathsf ABCDEFGHIJKLTUVWXYZ$
`\mathcal`	calligraphic letters	$\mathcal ABCDEFGHIJKLMWXYZ$
`\mathscr`	script letters	$\mathscr ABCDEFOPQR$
`\mathfrak`	Fraktur (old German style) letters	$\mathfrak ABCDVWXYZ$

Radical signs Use sqrt,
which adjusts to the size of its argument:\sqrt{x^3} x3 means: $\sqrt{x^3} x3$ ;
\sqrt[3]{\frac xy} means: $\sqrt[3]{\frac xy}$ .
For complicated expressions, consider using {...}^{1/2} instead.
Some special functions such as "lim", "sin", "max", "ln", and so on are normally set in roman font instead of italic font.
Use \lim, \sin, etc. to make these: \sin x: $\sin x$ , not sin x : $sin x$ .
Use subscripts to attach a notation to \lim: \lim_{x\to 0}: $\lim_{x\to 0}$

There are a very large number of special symbols and notations, too many to list here; see this shorter listing, or this exhaustive listing. Some of the most common include:

symbols	redered as
`\lt \gt \le \leq \leqq \leqslant \ge \geq \geqq \geqslant \neq`	$\lt \gt \le \leq \leqq \leqslant \ge \geq \geqq \geqslant \neq$
You can use \not to put a slash through almost anything: `\not\lt`	$\not\lt$ but it often looks bad
`\times \div \pm \mp`	$\times \div \pm \mp$ .
`\cdot` is a centered dot	$x \cdot y$
`\cup \cap \setminus \subset \subseteq \subsetneq \supset \in \notin \emptyset \varnothing`	$\cup \cap \setminus \subset \subseteq \subsetneq \supset \in \notin \emptyset \varnothing$
`{n+1 \choose 2k} or \binom{n+1}{2k} (n+12k)`	${n+1 \choose 2k} or \binom{n+1}{2k} (n+12k)$
`\to \rightarrow \leftarrow \Rightarrow \Leftarrow \mapsto`	$\to \rightarrow \leftarrow \Rightarrow \Leftarrow \mapsto$
`\land \lor \lnot \forall \exists \top \bot \vdash \vDash`	$\land \lor \lnot \forall \exists \top \bot \vdash \vDash$
`\star \ast \oplus \circ \bullet`	$\star \ast \oplus \circ \bullet$
`\approx \sim \simeq \cong \equiv \prec \lhd \therefore`	$\approx \sim \simeq \cong \equiv \prec \lhd \therefore$
`\infty \aleph_0`	$\infty \aleph_0$
`\nabla \partial`	$\nabla \partial$

For modular equivalence, use \pmod like this: a\equiv b\pmod n $a\equiv b\pmod n$ .
\ldots is the dots in a1,a2,…,an
\cdots is the dots in a1+a2+⋯+an
Some Greek letters have variant forms:
\epsilon \varepsilon: $\epsilon \varepsilon$ ,
\phi \varphi: $\phi \varphi$ ,
and others.
Script lowercase l is \ell $\ell$ .

Detexify lets you draw a symbol on a web page and then lists the TEX symbols that seem to resemble it.

These are not guaranteed to work in MathJax but are a good place to start. To check that a command is supported, note that MathJax.org maintains a list of currently supported LATEX commands, and one can also check Dr. Carol JVF Burns's page of TEX Commands Available in MathJax.

latex的数学符号整理

latex的数学符号整理

求和的公式表达

符号

There are a very large number of special symbols and notations, too many to list here; see this shorter listing, or this exhaustive listing. Some of the most common include:

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