交集和并集部分考点介绍
交集和并集 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 co... [ 查看全文 ]交集和并集部分考点介绍的相关文章
2013年4月新gre考试备考：gre数学考点之Roots of Polynomial
The number c is a root of a polynomial p(x), if p(c)=0. An n-th order polynomial has n complex roots. Example: 2 is a root of polynomial p(x)=x-2,since p(2)=2-2=0. 1 is a root of polynomial p(x)=x...[ 查看全文 ]
