y=2sin（2x-π/6）+1
∵x∈[π/3,π]
∴2π/3≤2x≤2π
π/2≤2x-π/6≤11π/6
当2x-π/6=π/2时,ymax=3
当2x-π/6=3π/2时,ymin=-1
函数值域为[-1,3]