(1)
F(x)=cos3x+√3sin3x+1
=2(1/2cos3x+√3/2sin3x)+1
=2(sin3xcosπ/6+cos3xsinπ/6)+1
=2sin(3x+π/6)+1
(2)
最小正周期T=2π/3=2π/3
最大值F最大=2+1=3
最小值F最小=-2+1=-1