y=sin2x+√3*cos2x
=2(1/2*sin2x+√3/2*cos2x)
=2sin(2x+π/3)
函数的周期为：T=2kπ/2=kπ,k为整数
∵-1≤sin(2x+π/3)≤1
∴函数的值域为：[-2,2]