已知向量 m =(sinx,-1),向量 n =( 3 cosx,- 1 2 ),函数f(x)=( m + n )? m . (1)求f(x)的最周期T; (2)已知a,b,c分别为△ABC内角A,B,C的对边,A为锐角,a=2 3 ,c=4,且f(A)恰是f(x)在[0, π 2 ]上的最大值,求A,b和△ABC的面积S.
【单选题】Lead Stories Two teams of Canadian engineers are completing their low-budget rockets and have begun seeking volunteer astronauts for a 2003 launch date to go 62 miles into space to win the St. Louis-b...