题目内容
已知集合A={5,6,7,8},设f,g都是由A到A的映射,其对应法则分别如表1和表2所示:
则与f[g(5)]值相同的为
A.g[f(5)]
B.g[f(6)]
C.g[f(7)]
D.g[f(8)]
理解映射概念中象、原象的意义.
已知集合A={1,2,3,4,5},B={(x,y)|x∈A,y∈A,x-y∈A};则B中所含元素的个数为( )
A.3 B.6
C.8 D.10
已知集合A={0,1,2,3,4,5},B={1,3,6,9},C={3,7,8},则(A∩B)∪C等于( )
(A){0,1,2,6,8} (B){3,7,8} (C){1,3,7,8} (D){1,3,6,7,8}
已知集合A={x|x<1或x>5},B={x|a≤x≤b},且A∪B=R,A∩B={x|5<x≤6},
则2a-b= .
已知集合A={0,1,2,3,4,5},B={1,3,6,9},C={3,7,8},则(A∩B)∪C等于 ( )
A.{0,1,2,6,8} B.{3,7,8} C.{1,3,7,8} D.{1,3,6,7,8}