-
实用文档
常用数学符号英文对照
Basic
math symbols
Symbol
Symbol
Name
Meaning / definition
Example
5 = 2+3
=
equals sign
equality
5 is equal to 2+3
5
≠
4
≠
not equal sign
inequality
5 is not equal to
4
sin
(0.01)
≈
0.01,
≈
approximately
equal
approximation
x
≈
y
means
x
is
approximately equal to
y
5 > 4
>
strict inequality
greater than
5 is greater
than 4
4 < 5
<
strict inequality
less than
4 is less than 5
5
≥
4,
≥
inequality
greater than or equal to
x
≥
y
means
x
is greater
than
or equal to
y
≤
4
≤
5,
inequality
less than or
equal to
x
≤
y
means
x
is greater
实用文档
than or
equal to
y
calculate expression
inside
first
calculate expression
inside first
( )
[ ]
+
?
±
±
*
×
·
÷
/
–
parentheses
2
×
(3+5) = 16
brackets
[(1+2)
×
(1+5)] =
18
plus sign
addition
1 + 1 = 2
minus sign
subtraction
2
?
1 = 1
plus - minus
both plus and
minus
operations
both minus
and plus
operations
3
±
5 = 8 and -2
minus - plus
3
±
5 = -2 and 8
asterisk
multiplication
2 * 3 = 6
times sign
multiplication
2
×
3 = 6
multiplication
dot
division sign
/
obelus
multiplication
2
·
3 = 6
division
6
÷
2 = 3
division slash
division
6 / 2 = 3
horizontal line
division / fraction
7 mod 2 = 1
mod
modulo
remainder calculation
.
period
decimal
point, decimal
separator
2.56 = 2+56/100
a
b
power
exponent
2
3
= 8
a^b
caret
exponent
2 ^ 3
= 8
实用文档
√
a
3
square root
√
a
·
√
a = a
√
9 =
±
3
√
a
cube root
3
√
a
·
3
√
a
·
3
√
a =
a
3
√
8
= 2
4
4
√
a
√
a
·
4
√
a
·
4
√
a
·
4
√
4
fourth root
√
16 =
±
2
a =
a
n-th root
(radical)
percent
n
√
a
for
n
=3,
n
√
8 = 2
10%
×
30 = 3
%
1% =
1/100
1
‰
= 1/1000 =
‰
per-mille
10
‰
×
30 = 0.3
0.1%
ppm
per-million
1ppm
= 1/1000000
10ppm
×
30 = 0.0003
1ppb =
ppb
per-
billion
1/1000000000
ppt
1ppt = 10
-12
10ppb
×
30 =
3
×
10
-7
per-trillion
10ppt
×
30 = 3
×
10
-10
Geometry symbols
Symbol
Symbol Name
Meaning /
definition
Example
∠
angle
formed by two rays
∠
ABC =
30
°
measured
angle
ABC =
30
°
spherical angle
AOB = 30
°
∟
right angle
= 90
°
α
=
90
°
实用文档
°
degree
1 turn =
360
°
α
= 60
°
deg
degree
1 turn
= 360deg
α
=
60deg
′
prime
arcminute, 1
°
= 60
′
α
=
60
°
59
′
α
= 60
°
59
′
″
double prime
arcsecond,
1
′
=
60
″
59
″
AB
line
infinite
line
line segment
line from point A to point B
⊥
| |
?
~
ray
line that start from
point A
arc
arc
from point A to point B
=
60
°
AC
⊥
BC
perpendicular
perpendicular
lines (90
°
angle)
parallel
parallel lines
AB | | CD
congruent to
equivalence of geometric shapes and
size
?
ABC
?
?
XYZ
similarity
same shapes, not same size
?
ABC~
?
XYZ
Δ
ABC
?
Δ
Δ
triangle
triangle shape
BCD
|
x
-
y
|
distance
π
pi constant
distance between points x and y
|
x
-
y
|
= 5
π
= 3.141592654...
is the ratio between the circumference
and
c
=
π
·
d
=
实用文档
diameter of a circle
2
·
π
·
r
360
°
=
2
π
rad
radians
radians angle unit
rad
c
radians
radians angle unit
360
°
=
2
π
c
360
°
=
400
grad
gradians /
gons
grads angle unit
grad
360
°
=
400
g
g
gradians /
gons
grads angle unit
Algebra symbols
Symbol
Symbol Name
Meaning /
definition
unknown value
to find
Example
x
≡
?
:=
~
≈
∝
∞
?
x variable
when 2
x
= 4, then
x
= 2
equivalence
identical to
11 ~ 10
equal
by definition
equal by
definition
equal by
definition
weak
approximation
equal by
definition
approximately equal
approximately equal
approximation
sin
(0.01)
≈
0.01
proportional to
proportional
to
y
∝
x
when
y
=
kx,
k
constant
lemniscate
infinity symbol
much less than
much less
than
1
?
1000000
实用文档
?
( )
much greater than
much
greater
than
calculate
1000000
?
1
parentheses
expression
inside first
calculate
2 * (3+5) = 16
[ ]
{ }
?
x
?
?
x
?
brackets
expression
inside first
[(1+2)*(1+5)] =
18
braces
set
rounds number
to lower
integer
rounds number
to
upper integer
factorial
floor brackets
?
4.3
?
= 4
ceiling brackets
?
4.3
?
= 5
x
!
|
x
|
exclamation mark
4! =
1*2*3*4 = 24
| -5 | = 5
single vertical bar
absolute
value
maps values of x
to
f(x)
f
(
x
)
function of x
f
(
x
) =
3
x
+5
f
(
x
)=3
x
,
g
(
x
)
=
x
-1
?
(
f
?
g
)(<
/p>
x
)=3(
x
-
1)
(
f
?
g
)
(
x
)
(
f
?
g
)
function composition
=
f
(
g
(<
/p>
x
))
(
a<
/p>
,
b
) =
(
a
,
b
)
open interval
x
∈
(2,6)
{
x
|
a
<
x
<
b
}
[
a
,
b
] =
[
a
,
b
]
closed interval
x
∈
[2,6]
{
x
|
a
≤
x
≤
b
}
change /
difference
?
?
∑
delta
?
t
=
t
1
-
t
0
discriminant
Δ
=
b
2
-
4
ac
summation -
sum of all values
sigma
∑
x
i
= x
1
+x
2
+...+x
n
实用文档
in
range of
series
double
summation
product -
∑∑
sigma
∏
capital pi
product of all
values in range
of series
∏
x
i
=x
1
·
x
2
·
...
·
x
n
e
e
=
e
constant
/ Euler's number
e
= lim (1+1/
x
)
x
,
x
→∞
2.718281828...
γ
=
γ
Euler-Mascheroni
constant
0.527721566...
φ
golden ratio
golden ratio
constant
π
=
3.141592654...
π
pi constant
is the ratio
between the
circumference
and diameter of a
circle
c
=
π
·
d
=
2
·
π
·
r<
/p>
Linear Algebra Symbols
Symbol
Symbol Name
Meaning / definition
Example
·
×
dot
scalar product
a
·
b
a
×
b
A
?
B
cross
vector product
A
?
B
tensor product
tensor
product of A and B
实用文档
[ ]
( )
|
A
|
det(
A
)
||
x
||
inner product
brackets
matrix of numbers
parentheses
matrix of numbers
determinant
determinant of
matrix A
determinant
determinant of
matrix A
double vertical bars
norm
A
T
A
?
A
*
A
-1
transpose
matrix transpose <
/p>
(
A
T
)
ij
=
(
A
)
ji
(
A
?
)
ij
=
(
A
)
ji
(
A
*
)
ij
=
(
A
)
ji
Hermitian matrix
matrix conjugate transpose
Hermitian matrix
matrix
conjugate transpose
inverse matrix
A A
-1
=
I
rank(
A
)
matrix rank
rank of matrix A
rank(
A
) = 3
dim(
U
)
dimension
dimension of
matrix A
rank(
U
)
= 3
Probability and statistics symbols
Symbol
Symbol Name
probability
function
probability of
Meaning /
definition
Example
P
(
A
)
P
(
A
∩
B
)
probability of event A
P
(
A
) =
0.5
events
intersection
probability that of
events A
and B
P
(
A
< br>∩
B
) = 0.5
P
(
A
∪
B
)
events union
probability of
probability that of
events A
or B
P
(
A
∪
B
) = 0.5
实用文档
conditional
P
(
A
|
B
)
probability
function
probability of
event A
given event B occured
P
(
A |
B
) = 0.3
probability
f
(
x
)
P
(
a
≤
x
≤
b
) =
∫
density function
(pdf)
f
(
x
)
dx
cumulative
F
(
x
)
μ
E
(
X
)
E
(
X |
Y
)
var
(
X
)
σ
2
distribution
function (cdf)
population
mean
expectation
value
F
(
x
) =
P
(
X
≤
x
)
mean of population
values
expected value of
random
variable X
expected value of
random variable X
given Y
variance of random
variable
X
variance of population
values
standard deviation of
random variable X
standard
deviation
value of random
variable X
middle value of
random variable x
covariance
of random
variables X and Y
correlation of random
variables X and Y
correlation of random
variables X and Y
μ
= 10
E
(
X
) =
10
conditional
expectation
E
(
X |
Y=2
) = 5
variance
var
(
X
)
= 4
variance
σ
2
= 4
std
(
X
)
σ
X
standard
deviation
std
(
X
)
= 2
standard
deviation
σ
X
=
2
median
cov
(
X
,
Y
< br>)
corr
(
X
,
Y
ρ
X
< br>,
Y
covariance
cov
(
X,Y
) = 4
)
correlation
correlation
corr
(
X,Y
) = 0.6
ρ
X
,
Y
= 0.6
-
-
-
-
-
-
-
-
-
上一篇：SCI收录的园艺类期刊
下一篇：2016年SCI收录土木工程期刊125种目录