解如图。
(1)T=2π/(1/2)=4π
(2)∵正弦函数的值域是[-1,1]
∴函数的最大值是2×1=2
此时:x/2 - π/3=2kπ + π/2
x/2=2kπ + 5π/6
∴x=4kπ + 5π/3,(k∈Z)
(3)f(π/2)=2sin[(π/2)/2 - π/3]
=2sin(π/4 - π/3)
=2[sin(π/4)cos(π/3) - cos(π/4)sin(π/3)]
=2[(√2/2)•(1/2) - (√2/2)•(√3/2)]
=√2/2 - √6/2=(√2 - √6)/2
见上图详细解释。