What is the symbol of high mathematics set

What is the symbol of high mathematics set

A set, or set, in which things are called elements or elements of a set. Any set is a subset of itself.
Element to collection relationship:
There are two kinds of relations between elements and sets: belonging and not belonging.
Classification of collections:
A set of elements called the union of A and B, denoted A∪B (or B∪A), and read A∪B={ x|x∈A, or x∈B}.
Intersection: The set of elements belonging to A and belonging to B is called the intersection (set) of A and B, which is recorded as A∩B (or B∩A), and is read as "A intersection B "(or" B intersection A "), i.e. A∩B={ x|x∈A, and x∈B}
For example, the complete set U ={1,2,3,4,5} A ={1,3,5} B ={1,2,5}. So since both A and B have 1,5, then A∩B ={1,5}. Again, they contain 1,2,3,5 elements, no matter how many they are, either you have them or I have them.
An infinite set: Definition: A set containing infinite elements is called an infinite set
A finite set: Let N+ be all positive integers and Nn={1,2,3,... If there is a positive integer n such that the set A corresponds to Nn, then A is called a finite set.
Difference: A set of elements that belong to A but not to B is called the difference between A and B
Note: Empty sets are contained in any set, but can not be said to belong to any set.
A set consisting of elements belonging to the complete set U but not belonging to the set A is called a complement of the set A, denoted as CuA, i.e. CuA={ x|x∈U, and x does not belong to A}
Empty sets are also considered to be finite sets.
For example, if the complete set U ={1,2,3,4,5} and A ={1,2,5}, then the 3,4 that the complete set has but not in A is CuA, is the complement of A.
In information technology, CuA is often written as ~A.
Some specified object sets become a set together. A set containing finite elements is called a finite set. A set containing infinite elements is called an infinite set. An empty set is a set containing no elements.
If all the elements of set A are elements of set B at the same time, then A is called a subset of B and A is written A B. If A is a subset of B and A is not equal to B, then A is called a true subset of B and A is written A B.
Respondent's Supplement 2009-07-17 16:29 Representation of sets: list method and description method.
1. Enumeration: It is usually used to represent a finite set. All elements in the set are listed one by one and written in curly brackets. This method of representing a set is called enumeration.{1,2,3,... }
2. Description method: It is commonly used to represent an infinite set. The common attributes of elements in the set are described in words, symbols or expressions, etc. and written in curly brackets. This method of representing the set is called description method.{ x|P }(x is the general form of the elements of the set, and P is the common attribute of the elements of the set). For example, the set composed of positive real numbers less than π is represented as:{ x|0

Mathematical Set Symbols of Senior One and Their Significance Don't link, just say

R real set Q rational set
Z integer set N natural number set
N+(or N*) positive integer set
An oblique line above the empty set circle (this symbol can not be printed)
∈ Belongs to x∈A x belongs to A, that is, x is an element of set A
∩Intersection of A∩B A and B
Union of A∪B A and B
COMPLEMENTARY SETS OF SUBSET A OF THE COMPLETE CuA NEUTRONS

R real set Q rational set
Z integer set N natural number set
N+(or N*) positive integer set
An oblique line above the empty circle
∈ Belongs to x∈A x belongs to A, that is, x is an element of set A
∩Intersection of A∩B A and B
Union of A∪B A and B
COMPLEMENTARY SETS OF SUBSET A IN CuA COMPLETE UNIT U

All Symbols of Senior One Mathematics Set

∈X∈A x belongs to A
{A, b, c... } Element a, b, c... Set of components
N natural number set
N + positive integer set
Z Integer Set
Q rational set
R real set
Union
∩Intersection
Closed interval of {a, b} a to b
Opening interval of (a, b) a to b
Value of f (x) function f at x
Mapping f: A→B Set A to Set B

∈X∈Ax belongs to A
{A, b, c... } Element a, b, c... Set of components
N natural number set
N + positive integer set
Z Integer Set
Q rational set
R real set
Union
∩Intersection
Closed interval of {a, b} a to b
Opening interval of (a, b) a to b
Value of f (x) function f at x
Mapping f: A→B Set A to Set B

Plane vector judgment problem 1 If b=λa, then a‖b; 2 If a‖b, then there are countless λs such that a=λb Please state your reasons

A pair is a theorem.
2 No, there is only one real number λ

The moduli of the three vectors a, b, c on a given plane are all 1, and the angles between them are all 120 degrees. 1. Verification (a-b) vertical c 2. If │ka+b+c│>1(k∈R). The moduli of the three vectors a.b.c on a given plane are all 1, and the angles between them are all 120 degrees. 1. Verify (a-b) vertical c 2. If │ka+b+c│>1(k∈R).

(1) The sum of three vectors is zero vector.
,(A-b)*c=ac-bc=|a||c|cos120°-|b||c|cos120°=0
So (a-b) vertical c
(2)│Ka+b+c│b, c angle is 120°
Synthesize b+c =-a
Since that vector is collinear,
│Ka+b+c│=│ka-a│=a (k-1)>1
│A│=1
So (k-1)>1
K >2

Please judge the correctness of the following two questions and explain the reasons. (1) AB BA =0(). (2)0• AB →=0()(Since the vector symbol "→" can not be marked above the letter, it can only be written immediately after the letter, please understand. The second question is based on "when λ>0, the direction of λ a is the same as the direction of a; when λ<0, the direction of λ a is opposite to the direction of a; when λ=0,λ a=0." Please specify,)

(1) Is a zero vector, not equal to zero.
(2)0• AB →= zero vector.
In summary, you need to understand the concept of zero vector and the difference with zero.

(1) Is a zero vector, not equal to zero.
(2)0• AB →= zero vector.
In summary, you need to understand the concept of zero vector and the difference from zero.