The invention and use of is later than the number, but its number exceeds the number. Now there are more than 200 commonly used mathematical symbols, each of which has an interesting experience.
So are mathematical symbols.
exceed
For example, for example:
1, operation symbol
Such as a plus sign (+),
minus sign
(-),
Multiplication/Multiplication/Time Symbol (×)
(x or ...),
Signs of division
(÷ or/), union of two sets (∩), intersection (∩),
Root/root symbol ()
(√), logarithm (log, lg, ln, lb), ratio (:),
Sign of absolute value
|
|, differential (d), integral (∵), closed surface (curve) integral (∮), etc.
2、
Relational character
For example, "=" is an equal sign and "√" is an approximate symbol (i.e.
proximate
), "≦" is
A sign of inequality
, "> is greater than sign,"
"Indicates the changing trend of variables," "is a similar symbol," ≒ "is a complete equal sign," ∨ "is a parallel symbol," is a vertical symbol, "∧" is.
direct ratio
Symbol (indicating
proportion
Reciprocal relation can be used), "∑" is the symbol, "?" Contained in the symbol "?" Where is the inclusion symbol, "|" means "may".
separable
"(for example, a|b
It means "A is divisible by B", while ||b means that R is the greatest power of A divisible by B), and any letter such as X and Y can represent an unknown number.
3, combined with symbols
Such as bracket "()",
support
"[
]",
brace
"{
} ",horizontal line"-"
4. Natural symbols
Such as the plus sign "+",
negative sign
"-",
sign symbol
Wait a minute.
Step 5 omit symbols
Such as a delta,
right triangle
(Rt△), sine (sin) (see
trigonometric function
),
hyperbolic sine function
Function of (sinh), x (f(x)), limit (lim), angle (∞), ∫.
Because, ⅷ
So wait.
6、
permutation and combination
sign
C
Number of combinations
, one
(or p)
number of permutations
，n
Total number of elements, r
Number of elements participating in the selection!
factorial
Wait a minute.
7、
Discrete mathematics
sign
Like what?
Universal quantifier
,?
Existential quantifier
,├
Determinant (formula can be proved by L), μ
Satisfier (the formula is valid on E, and the formula can be satisfied on E), ﹁
The proposition of "not" operation, such as
negative proposition
?﹁p
Proposition "
combine
"("and ") operation, ∨
Proposition "
draw
"("or ","or ") operation, →
The "conditional" operation of the proposition?
The "double condition" operation of proposition, etc.