(LaTex)
将数学公式写在$$之间，代表的是插入行内数学公式。
将数学公式写在$$ $$之间，会使公式独立成一行并强制居中。
$leftvert a
ightvert$
(leftvert a ightvert)
$lVert z
Vert$
(lVert z Vert)
$infty$
(infty)
$aequiv bpmod c$
(aequiv bpmod c)
$amod b$
(amod b)
$mid
mid shortmid
shortmid$
(mid mid shortmid shortmid)
$sqrt{2} sqrt[n]{x}$
(sqrt{2} sqrt[n]{x})
$pm mp dotplus$
(pm mp dotplus)
$ imes div divideontimes$
( imes div divideontimes)
$in
otin
i
ot
i$
(in otin i ot i)
$cap Cap sqcap igcap$
(cap Cap sqcap igcap)
$cup Cup sqcup igcup igsqcup uplus iguplus$
(cup Cup sqcup igcup igsqcup uplus iguplus)
$subset Subset sqsubset$
(subset Subset sqsubset)
$supset Supset sqsupset$
(supset Supset sqsupset)
$subseteq
subseteq subsetneq varsubsetneq sqsubseteq$
(subseteq subseteq subsetneq varsubsetneq sqsubseteq)
$supseteq
supseteq supsetneq varsupsetneq sqsupseteq$
(supseteq supseteq supsetneq varsupsetneq sqsupseteq)
$subseteqq
subseteqq subsetneqq varsubsetneqq$
(subseteqq subseteqq subsetneqq varsubsetneqq)
$supseteqq
supseteqq supsetneqq varsupsetneqq$
(supseteqq supseteqq supsetneqq varsupsetneqq)
$
e
eq equiv
otequiv$
( e eq equiv otequiv)
$sim
sim acksim hicksim simeq acksimeq eqsim cong
cong$
(sim sim acksim hicksim simeq acksimeq eqsim cong cong)
$approx hickapprox approxeq asymp propto varpropto$
(approx hickapprox approxeq asymp propto varpropto)
$leqslant geqslant$
(leqslant geqslant)
$forall herefore ecause And$
(forall herefore ecause And)
$overline{abc} underline{abc}$
(overline{abc} underline{abc})
$a^2$
(a^2)
$a_2$
(a_2)
${}^2_1!X^3_4$
({}^2_1!X^3_4)
$vec{x} overleftarrow{AB} overrightarrow{AB} widehat{AB}$
(vec{x} overleftarrow{AB} overrightarrow{AB} widehat{AB})
$overset{frown}{AB}$
(overset{frown}{AB})
$overbrace{1+2+cdots+100}$
(overbrace{1+2+cdots+100})
$egin{matrix}5050\overbrace{1+2+cdots+100}end{matrix}$
(egin{matrix}5050\overbrace{1+2+cdots+100}end{matrix})
$underbrace{1+2+cdots+100}$
(underbrace{1+2+cdots+100})
$egin{matrix}underbrace{1+2+cdots+100}\5050end{matrix}$
(egin{matrix}underbrace{1+2+cdots+100}\5050end{matrix})
$sum_{i=1}^na_i sumlimits_{i=1}^na_i$
(sum_{i=1}^na_i sumlimits_{i=1}^na_i)
$prod_{i=1}^na_i prodlimits_{i=1}^na_i$
(prod_{i=1}^na_i prodlimits_{i=1}^na_i)
$lim_{n oinfty}a_i limlimits_{n oinfty}a_i$
(lim_{n oinfty}a_i limlimits_{n oinfty}a_i)
$int_{-N}^{N}a^x\,dx$
(int_{-N}^{N}a^x\,dx)
$frac{1}{2}$
(frac{1}{2})
$dbinom{n}{m}$
(dbinom{n}{m})
$egin{vmatrix}a&b\c&dend{vmatrix}$
(egin{vmatrix}a&b\c&dend{vmatrix})
$egin{bmatrix}a&cdots&b\vdots&ddots&vdots\c&cdots&dend{bmatrix}$
(egin{bmatrix}a&cdots&b\vdots&ddots&vdots\c&cdots&dend{bmatrix})
$egin{Bmatrix}a&c\b&dend{Bmatrix}$
(egin{Bmatrix}a&c\b&dend{Bmatrix})
$egin{pmatrix}a&c\b&dend{pmatrix}$
(egin{pmatrix}a&c\b&dend{pmatrix})
egin{cases}x-1&xleqslant3\x^2+3x-1&x>3end{cases}
egin{cases}x-1&xleqslant3x^2+3x-1&x>3end{cases}
egin{cases}2x+9y-5z=10\4x+20y+z=24\x-frac{1}{2}y+3z=8end{cases}
egin{cases}2x+9y-5z=104x+20y+z=24x-frac{1}{2}y+3z=8end{cases}
$egin{aligned}f(x)&=(x+1)^2\&=x^2+2x+1end{aligned}$
(egin{aligned}f(x)&=(x+1)^2\&=x^2+2x+1end{aligned})
$egin{aligned}a_1&=1\a_2&=2\&dots\a_n&=nend{aligned}$
(egin{aligned}a_1&=1\a_2&=2\&dots\a_n&=nend{aligned})
$egin{array}{|c|c||c|}x&y&z\8&2&4\2&3&9\10&frac{3}{4}&sqrt{3}\a&b&cend{array}$
(egin{array}{|c|c||c|}x&y&z\8&2&4\2&3&9\10&frac{3}{4}&sqrt{3}\a&b&cend{array})
$alphaetagammadeltaepsilonzetaeta heta$
(alphaetagammadeltaepsilonzetaeta heta)
$oxed{sumlimits_{i=1}^{n}i=frac{n(n-1)}{2}}$
(oxed{sumlimits_{i=1}^{n}i=frac{n(n-1)}{2}})
常用的大概就那么多，其他的自己百度吧。