y=√3sinxcosx+cos²x
=(√3/2)sin2x+(1+cos2x)/2
=1/2+[(sin2x·(√3/2)+cos2x·(1/2)]
=1/2+(sin2xcos30°+cos2xsin30°)
=1/2+sin(2x+30°).
∴sin(2x+30°)=1时,y|max=3/2;
sin(2x+30°)=-1时,y|min=1/2.
最小正周期:T=2π/2=π.
y=√3sinxcosx+cos²x
=(√3/2)sin2x+(1+cos2x)/2
=1/2+[(sin2x·(√3/2)+cos2x·(1/2)]
=1/2+(sin2xcos30°+cos2xsin30°)
=1/2+sin(2x+30°).
∴sin(2x+30°)=1时,y|max=3/2;
sin(2x+30°)=-1时,y|min=1/2.
最小正周期:T=2π/2=π.