设函数f(x)=Asin()(A>0,>0,-<<)的图象关于直线x=对称,且周期为π,则f(x)( )
已知函数,则 =( )
已知正方体的外接球的体积是,则这个正方体的棱长是 ( )
设等差数列的前n 项和为,若,2,也成等差数列,则等于 ( )
已知复数z满足,则z = ( )
若集合M = {x ∈R | 2 x ≥ 4},N = {x∈R | x 2 - 4 x + 3 ≥ 0},则M∩N =( )