Question

设全集U={小于9的正整数},A={1.2.3},B={3.4.5.6},求AUB,Cu(AuB)

Answer 1

U={1,2,3,4,5,6,7,8}A∪B是A和B中元素的和, ∴A∪B={1,2,3,4,5,6}Cu(A∪B)是U中除了A∪B之外的元素, ∴Cu(A∪B)={7,8}