新GRE数学的要点:交集和并集

对于新GRE数学的要点:交集和并集，以下就是由美嘉导师带来的详细介绍：

新GRE数学要点：

Intersection of Sets

Intersection of two sets is another set with only the members that are in both sets. If the two sets do not share any common member， the intersection is the empty set with no member.

Example：

Intersection of {1，2，3} and {2，3，5} is the set {2，3}。

Intersection of the set with all primes and the set with all even numbers is the set {2} since only 2 is both even and prime.

Intersection of {1，2，3} and {4，5，6} is the empty set {}

Remember：

Intersection contains only the common members.

Two sets are disjoint if they have no member in common， that is they have an empty intersection.

union   of Sets

union   of two sets is another set with all the members from both sets.