《离散数学》试题及答案.doc

文档介绍：一、填空题
1 设集合A,B,其中A={1,2,3}, B= {1,2}, 则A - B=____________________; r(A) - r(B)= __________________________ .
2. 设有限集合A, |A| = n, 则|r(A×A)| = __________________________.
3. 设集合A = {a, b}, B = {1, 2}, 则从A到B的所有映射是__________________________ _____________, 其中双射的是__________________________.
4. 已知命题公式G=Ø(P®Q)∧R,则G的主析取范式是_______________________________
__________________________________________________________.
,G有7个点,其中4个叶点,则G的总度数为__________,分枝点数为________________.
6 设A、B为两个集合, A= {1,2,4}, B = {3,4}, 则从AÇB=_________________________; AÈB=_________________________;A-B= _____________________ .
7. 设R是集合A上的等价关系,则R所具有的关系的三个特性是______________________, ________________________, _______________________________.
8. 设命题公式G=Ø(P®(QÙR)),则使公式G为真的解释有__________________________,_____________________________, __________________________.
9. 设集合A={1,2,3,4}, A上的关系R1 = {(1,4),(2,3),(3,2)}, R1 = {(2,1),(3,2),(4,3)}, 则 R1·R2 = ________________________,R2·R1 =____________________________, R12 =________________________.
10. 设有限集A, B,|A| = m, |B| = n, 则| |r(A´B)| = _____________________________.
11 设A,B,R是三个集合,其中R是实数集,A = {x | -1≤x≤1, xÎR}, B = {x | 0≤x < 2, xÎR},则A-B = __________________________ , B-A = __________________________ ,
A∩B = __________________________ , .
13. 设集合A={2, 3, 4, 5, 6},R是A上的整除,则R以集合形式(列举法)记为___________ _______________________________________________________.
14.