解题思路:①由f(x)=4sin(2x+[π/3])的周期为π,可知当f(x1)=f(x2)=0时,x1-x2必是[π/2]的整数倍,可判断②的正误;
②利用诱导公式可知f(x)=4sin(2x+[π/3])=4cos[[π/2]-(2x+[π/3])]=4cos([π/6]-2x)=4cos(2x-[π/6]),从而可判断③的正误;
③f(-[π/6])=0可判断③的正误;
④利用f(-[2π/3])=0可判断④的正误
①∵f(x)=4sin(2x+[π/3])的周期T=[2π/2]=π,
∴由f(x1)=f(x2)=0可得x1-x2必是[π/2]的整数倍,故①错误;
②∵f(x)=4sin(2x+[π/3])=4cos[[π/2]-(2x+[π/3])]=4cos([π/6]-2x)=4cos(2x-[π/6]),
∴y=f(x)的表达式可改写为f(x)=4cos(2x-[π/6]),即②正确;
③∵f(-[π/6])=4sin[2×(-[π/6])+[π/3]]=0,∴y=f(x)的图象关于点(-[π/6],0)对称,即③正确;
④∵f(-[2π/3])=4sin[2×(-[2π/3])+[π/3]]=0,不是最值,∴y=f(x)的图象不关于直线x=-[2π/3]对称,即④错误;
综上所述,以上命题成立的序号是②③.
故答案为:②③
点评:
本题考点: 命题的真假判断与应用.
考点点评: 本题考查命题的真假判断与应用,着重考查正弦函数的周期性、对称性的综合应用,属于中档题.