Solutions to computing problems:
CrA={x|x≤ 1 or x≥3}, CuB={x|-2≤x≤4}? Assumption =CrB
∴ ? CrA∩CuB={x|-2≤x≤ 1 or 3≤x≤4}
Every element in CrA∪CrB = R∶R belongs to CrA∪CrB, and vice versa.
Extended data:
The nature of the set:
1. Certainty: Every object can determine whether it is an element of a set. Without certainty, it cannot be a set. For example, "tall classmates" and "small numbers" cannot form a set. This property is mainly used to judge whether a set can constitute a set.
2. Relevance: Any two elements in the set are different objects. If written as {1, 1, 2}, it is equivalent to {1, 2}. Being different from each other makes the elements in the collection not repeat. When two identical objects are in the same set, they can only be counted as an element of this set.
3. Disorder: {a, b, c}{c, b, a} are the same set.
4. Purity: The purity of the so-called set is represented by an example. Set a = {x | x
5, integrity: still use the above example, all in line with X.