The definition in mathematics is a set composed of all elements belonging to set A and set B, which is called the intersection of A and B. It is an intersection symbol and a common symbol in high school mathematics learning sets.

Basic definition:

The intersection of a and b is written as "A ∩B" Representation: A formally crosses b:Ax+b = y-a, and X belongs to B.

For example, the intersection of sets {1, 2,3} and {2,3,4} is {2,3}. The number 9 does not belong to the intersection of prime set {2, 3, 5, 7, 1 1, …} and odd set {1, 3, 5, 7, 9,1,…}.

If the intersection of two sets A and B is empty, that is, they have no common elements, then they do not intersect. Oslash。 For example, the set {1, 2} and {3,4} do not intersect, and the writing {1, 2} ∩ {3,4} =&; Oslash。

More generally, intersection operations can be performed on multiple collections at the same time. For example, the intersection of sets a, b, c and d is A ∩B ∩C ∩D = A ∩(B ∩(C ∩D)). The intersection operation satisfies the associative law, that is, a ∩ (b ∩ c) = (a ∩ b) ∩ c c.

Extended data:

The input method of ∩:

1, switch the computer input method to sogou input method;

2. Place the mouse cursor anywhere in the status bar of sogou input method, and then click the right mouse button;

3. On the pop-up page, click "Expression &; Symbol ";

4. Then click "Symbol Daquan";

5. After entering the symbol encyclopedia, click "Mathematics/Unit" on the left, and you will see ∩ on the right. Click it to select an entry.

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