设集合U={0,l,2,3,4,5,6},M ={l,3,5},N={4,5,6},则=( )
,则="(" )
曲线在点(1,1)处的切线的斜率为( )
="(" )
已知非零向量满足且,则为()
已知,直线和P(7,0),则点P到直线距离的取值范围是()