命题“若x2+y2=0,则x,y全为0”的否命题是( ) A.若x2+y2≠0,
问题:
命题“若x2+y2=0,则x,y全为0”的否命题是( )
A.若x2+y2≠0,则x,y全不为0
B.若x2+y2≠0,则x,y不全为0
C.若x2+y2≠0,则x,y至少有一个为0
D.若x,y不全为0,则x2+y2≠0
命题“若x2+y2=0,则x,y全为0”的否命题是( )
A.若x2+y2≠0,则x,y全不为0
B.若x2+y2≠0,则x,y不全为0
C.若x2+y2≠0,则x,y至少有一个为0
D.若x,y不全为0,则x2+y2≠0