f(x)
=2sinx/2cosx/2√3cosx
=sin(x/2 x/2) √3cosx
=sinx √3cosx
=√(1^2 √3^2)sin(x π/3)
=2sin(x π/3)
函数f(x)的最小正周期 T=2π/1=2π
f(x)的值域 [-2,2]