f(x)=sin^2x+sinxcosx+2cos^2x =1+1/2sin2x+cos^2x=1+1/2sin2x+1/2(cos2x+1)=3/2+1/2(sin2x+cos2x)=3/2+根号2/2(根号2/2sin2x+根号2/2cos2x)=3/2+根号2/2sin(2x+π/4)（1）最小正周期：T=2π/2=π（2）f(x)=3/2+根号...