Like' A_B%': it means to find the first string with' a' and the third string with' b'.
! =,<& gt: Not equal to
: =: Assignment
& gt& lt=: Understand by yourself.
''': the kind of mathematical symbol that represents the character.
The sign of (1) quantity: I, 2+i, A, X, natural logarithm base E, pi.
(2) Operation symbols: such as plus sign (+), minus sign (-), multiplication sign (× or), division sign (÷ or/), union of two sets (∩), intersection (∩), root sign (√), logarithm (log, lg, ln.
(3) relational symbols: such as "=" is an equal sign, "≈" is an approximate sign, "≦" is an unequal sign and ">" is a greater than sign. "
(4) Combination symbols: such as "()" in brackets "[]" and "-"in braces "{}".
(5) Natural symbols: such as positive sign "+",negative sign "-"and absolute value symbol "∨"
(6) Omitting symbols: such as triangle (△), sine (sin), cosine (cos), function of x (f(x)), limit (lim), so (∵), sum (∏) and multiplication (∏). ) and so on.
(7) Other symbols: α, β, γ, etc.
The meaning of mathematical symbols
symbolic meaning
∞ infinity
π pi
|x| absolute value
Union
intersection
≥ greater than or equal to
≤ less than or equal to
≡ Constant is equal to or congruent with.
Ln(x) logarithm based on e
Lg(x) logarithm based on 10
Integer function on floor (x)
Integer function under ceil(x)
X mod y of remainder
X-floor(x) fractional part
∫f(x)dx indefinite integral
The definite integral of ∫[a:b]f(x)dx a to b
& gt& gt is much larger than this figure.
& lt& lt is much smaller than the sign.
6? 7 including
circle
φ diameter
Beta beta
The wide application of mathematical symbols
If p is true, it is equal to 1, otherwise it is equal to 0.
∑[ 1≤k≤n]f(k) and n can be extended to many situations.
For example, ∑ [n is a prime number] [n
∑∑[ 1≤i≤j≤n]n^2
lim f(x)(x-& gt； ? ) seek the limit
M-order derivative function of f(z) f about z
C(n:m) combination number, where m is taken from n.
P(n:m) permutation number
Divisible by n
M⊥n coprime
A ∈ A a belongs to set A.
#A See if there are enough elements in set A? Hehe,,,,, remember to adopt! I work hard! Hey hey. . . . . Just kidding.