“若x2=1,则x=1或x=-1”的否命题是 [ ] A.若x2≠1,则x=1或
题型:选择题
问题:
“若x2=1,则x=1或x=-1”的否命题是 [ ]
A.若x2≠1,则x=1或x=-1
B.若x2=1,则x≠1且x≠-1
C.若x2≠1,则x≠1或x≠-1
D.若x2≠1,则x≠1且x≠-1
“若x2=1,则x=1或x=-1”的否命题是 [ ]
A.若x2≠1,则x=1或x=-1
B.若x2=1,则x≠1且x≠-1
C.若x2≠1,则x≠1或x≠-1
D.若x2≠1,则x≠1且x≠-1