How to pronounce θ? What do you mean?

θ ? Greek alphabet

Siduo

Theta (capital θ, lowercase θ), in Greek, is the eighth Greek letter.

Capital theta is:

Five quarks are represented by θ+in particle physics.

The lowercase theta is:

The angle that often represents a plane in mathematics.

Silent tooth fricative sound in international phonetic alphabet

Cyrillic? It's from Sita.

θ stands for:

Angle in geometry

The angle between the x axis and the xy plane in a spherical coordinate system or a cylindrical coordinate system.

Potential temperature in thermodynamics

Engineering uses θ as mean time between failure.

soil moisture

debye temperature

θ function

The invention and use of mathematical symbols are later than numbers, but their number exceeds numbers. Now there are more than 200 commonly used mathematical symbols, each of which has an interesting experience.

α α: α α

ββ:ββ

γγ:γγ

δ δ: δ Delta

εε:εε

ζ ζ: Jetta Zeta

ε η: Itaeta

θ θ: West Tower θ

ι ι: Aiota Iota

κ κ κ: kappa kappa kappa

∧λ:λλλλ

μ μ: Jiang Mumu

ν ν: Anger

ξ ξ: Cauchy xi

οο: Omicron, European Michael Wheel

∏π:π

ρ ρ: Soft ρ

Sigma σ: Sigma Sigma

τ τ: Set τ

υ υ: Yupuxilong

Φ φ: Φ φ.

χ χ: organ qi

ψ ψ: Psy Psi

ωω:ωω。

The development of 1

For example, there used to be several kinds of plus signs, but now the "+"sign is widely used. ? The mathematical symbol "+"comes from the Latin "et" (meaning "and"). Sixteenth century, Italian scientist? Nicolo Tartaglia uses the first letter of the Italian word "plu" (meaning "plus") to mean "plus", and the grass is "μ", which finally becomes "+". The number "-"is derived from the Latin word "minus" (meaning "minus"). It was abbreviated to M at first, but later it was simplified to "-"because it was written quickly.

It is also said that wine merchants use "-"to indicate how much a barrel of wine costs. After the new wine is poured into the vat, a vertical line is added to the "-",which means that the original line is erased, thus becoming a "+"sign.

/kloc-In the 5th century, the German mathematician Wei Demei officially determined "+"as the plus sign and "-"as the? Negative sign

Multiplication has been used for more than a dozen times, and there are two kinds of modern mathematics. One is "x", which was first proposed by British mathematician orcutt on 163 1; One is "",which was first created by British mathematician heriott. Leibniz, a German mathematician, thinks that "×", like the Latin letter "X", may cause confusion and opposes the use of "×" (in fact, point multiplication is also easily confused with decimal point in some cases). Later, he also proposed to use "∩" to represent multiplication. Does this symbol have any application in modern times? Set theory is right.

In the eighteenth century, the American mathematician Audley determined? "×" is a multiplication symbol. He believes that "×" is the rotational deformation of "+"and another symbol of addition.

""was originally used as a minus sign and has been popular in continental Europe for a long time. Until 163 1 year, the British mathematician Orkut used ":"to represent division or ratio, while others used "-"(except lines) to represent division. Later, the Swiss mathematician Laha, in his Algebra, officially regarded "∫" as the creation of the public? Division number.

The square root number was once represented by the combination of the first and second letters of the Latin root. At the beginning of the seventeenth century, a French mathematician? Descartes is in his book? Geometry, first time? "√" indicates the root sign. "√" is a variant of Latin word line "R", and "~" is a line enclosed.

/kloc-it was used by French mathematician Viette in the 6th century? "=" indicates the difference between two quantities. But what about Britain? Calder, a professor of mathematics and rhetoric at Oxford University, thinks that it is most appropriate to use two parallel and equal straight lines to indicate that two numbers are equal, so the equal sign "=" has been used since 1540.

159 1 year, French mathematician? David used this symbol extensively in the diamond, and it was gradually accepted by people. "=" was widely used in Leibniz, Germany in the17th century. Is it still used in geometry? ""means similar, use? "≒" means congruence.

Greater than the number? "> and less than sign?" & lt "was invented by the famous British mathematician heriott in 163 1 year. As for it? The three symbols "≥", ≤ "and ≦" appeared very late. Braces? "{}" and brackets? "[]" was created by Wei Zhide, one of the founders of algebra.

Any number (full name quantifier)? Judging from the word any in English, because lowercase and uppercase are easily confused, the first letter of this word is capitalized and then reversed. Similarly, existential number (existential quantifier)? Reverse writing of e from the word exist.

Two symbol types

edit

Quantitative symbol

Mathematical symbols such as: I,

, a, x, e, π. See below for details.

Operation symbol

Such as the plus sign (+),? Minus sign (-)? Multiplication symbol (× or),? Division sign (÷ or/), union (∩), intersection (∩), root sign (√), logarithm (log, lg, ln, lb), ratio (:),? Absolute value sign ||, differential (d), integral (), closed surface (curve) integral (∮), etc.

Relational character

For example, "=" is an equal sign, ""is an approximate symbol (that is, approximately equal to), and "≦" is? The unequal sign ">" is a greater than sign.

||b means that r is the greatest power of a divisible by b). Any letter such as x and y can represent an unknown number.

Combination symbol

Such as parentheses "()",? Square brackets "[]",? Brace "{}", horizontal line "-",as shown in figure.

Natural symbol

Like the plus sign "+"? Negative sign "-",? Signature "

"(and the corresponding minus sign)

leave out

Such as triangle (△), right triangle (Rt△), sine (? Sin) (see? Trigonometric function),

mathematical symbol

Hyperbolic sine function (? sinh)，？ x(？ F(x)), limit (? Lim), angle (∞),

Because (one foot can't stand)

So (if you stand on two feet, you can stand) (formula: because you can't stand, you have two points; Because the top two points, the bottom two points)

Sum, add: ∑, quadrature, multiply: ∏, take out all different R elements from N elements? Number of combinations

(? Total number of n elements; ? Number of elements participating in selection), power

Wait a minute.

Permutation and combination symbol

C combination number

A (or p)? number of permutations

n？ Total number of elements

r？ Number of elements participating in the selection

! ? Factorial, such as 5! =5×4×3×2× 1= 120, specify 0! = 1

! ! Half factorial (also called double factorial), for example, 7! ! =7×5×3× 1= 105, 10! ! = 10×8×6×4×2=3840

Discrete mathematical symbol

Universal quantifier

Existential quantifier

├ determinant (where is the formula? L can prove)

Satisfier (formula in? It works for e, where is the formula? E can satisfy)

The negation of a proposition, such as? What is the negation of the proposition? p

Propositional ∧ " Conjunction "("and ") operation

"∨" of the proposition? Disjunctive "(or, or) operation

→ "Conditional" Operation Proposition

"Double Condition" Operation of Proposition

p & lt= & gt？ q？ Proposition? P and? Equivalence relation of q

p = & gt？ q？ Proposition? P and? Implication relation of q (p is a sufficient condition of q and q is a necessary condition of p)

A* formula? The dual formula of A, or the reciprocal of number theory of A (this can also be written as

)

wff？ Combination formula

if and only if

"NAND" operation of proposition ("NAND gate")

A proposition that does not operate ("? NOR gate ")

□ The modal particle "inevitable"

The modal particle "may"

null set

∈ belongs to (such as "? One? B ",that is"? A belongs to? b”)

Do not belong to

p(？ A) assembly? Power set of a

|? A | conference? Point of a

r？ =R○R [R =R ○R] the "compound" of relation R.

Alef Alef

include

(or? )? True tolerance

In addition, there are corresponding? ,? ,? wait for

Union operation of ∪ set

U(P) stands for the domain of p.

Intersection operation of ∩ set

Differential operation of -or \ set

(12 10) restriction

Start dealing with relationships? Equivalence class of r

A/？ r？ Assembly? What's on a? Quotient set of r

[? A] element? Made by a? cyclic group

I rang, ideal.

Z/(？ N) mode? Congruence class set of n

r(？ R) relationship? R's reflexivity? close

s(？ R) relationship? Symmetric closure of r

Deductive theorem of CP proposition (CP rule)

EG Existential Generalization Rule (Existential Quantifier Introduction Rule)

ES existential quantifier specific rule (existential quantifier elimination rule)

UG full name promotion rules (? The introduction rules of universal quantifiers)

American full name specific rule (full name quantifier elimination rule)

R relation

R- compatible relation

R○S relation and its combination

Domf function? Domain (pre-domain)

Ranf function? range

f:？ x→? y？ F is? X to? Function of y

(? x，？ y)？ X and? y？ The greatest common divisor is sometimes used to avoid confusion. gcd(x，y)

[? x，？ y]？ X and? y？ Least common multiple, sometimes used to avoid confusion? lcm(x，y)

Ah (? Ha)? About what? Left (right) of A? coset

Ker(？ f)？ Homomorphic mapping? The core of f (or? F homomorphic kernel)

[ 1,? N] 1 to? Integer set of n

d(？ First,? b)，|？ AB|, or? AB？ Point? A and point? The distance between b

d(？ V) point? Degree of v

G=(？ v，？ E) What is a point set? V, what is the edge set? E's diagram? G

w(？ G) figure? Connected branch number of g

k(？ G) figure? Point connectivity of g

Δ(? G) figure? Maximum vertex degree of g

One (? G) figure? Adjacency matrix of g

P(G) diagram? Reachable matrix of g

m(？ G) figure? Incidence matrix of g

c？ Complex set

Me? Imaginary number set

n？ Natural number set, a non-negative integer set (containing the element "0")

N*？ n？ +) positive natural number set, positive integer set (where * means to remove the element "0" from the set, such as? R* stands for non-zero real number)

p？ Prime number (? Prime number) set

q？ Rational number set

r？ Real number set

z？ Integer set

Collection category

Top？ Topological space category

Ab？ Commutative group category

Grp group category

Mon unit semigroup category

Category of (associative) rings with identity elements in rings

Rng ring category

c？ Rng commutative ring category