定义A-B = {x| x A,且x B},若A =" {2," 4, 6, 8, 10},B =" {1," 4, 8},则A-B等于(2)
若曲线在点处的切线方程是,则( )
sin(-x)=,则sin2x的值为 ( )A. B. C. D.
已知向量不共线,,,如果,那么 ( )
若集合M={x∈R|-3<x<1},N={x∈Z|-1≤x≤2},则M∩N= ( )
已知,,则( )