若函数的图象与x轴有公共点,则m的取值范围是()
A.m≤-1 | B.-1≤m<0 | C.m≥1 | D.0<m≤1 |
已知函数f(x)= x2+ lg(x+), 若f(a)="M," 则f(-a)= ( )
A. 2a2-M | B.M-2a2 | C.2 M-a2 | D.a2-2M |
已知命题p:函数的值域为R,命题q:函数
是减函数。若p或q为真命题,p且q为假命题,则实数a的取值范围是
A.a≤1 | B.a<2 | C.1<a<2 | D.a≤1或a≥2 |
设f:x→y=2x是A→B的映射,已知集合B={0,1,2,3,4},则A满足()
A.A={1,2,4,8,16} | B.A={0,1,2,log23} |
C.A![]() |
D.不存在满足条件的集合 |
下列关系中正确的是()
A.(![]() ![]() ![]() ![]() ![]() ![]() |
B.(![]() ![]() ![]() ![]() ![]() ![]() |
C.(![]() ![]() ![]() ![]() ![]() ![]() |
D.(![]() ![]() ![]() ![]() ![]() ![]() |