解
y=1/2cos²x+√3/2sinxcosx+1
=√3/4(2sinxcosx)+1/4(2cos²x-1)+5/4
=√3/4sin2x+1/4cos2x+5/4
=1/2(√3/2sin2x+1/2cos2x)+5/4
=1/2(sin2xcosπ/6+cos2xsinπ/6)+5/4
=1/2sin(2x+π/6)+5/4
∴振幅是1/2,周期T=2π/2=π
x∈[0,π]
∴2x+π/6∈[π/6,13π/6]
∴sin(2x+π/6)∈[-1,1]
当sin(2x+π/6)=1时,即2x+π/6=π/2
y取得最大值,ymax=1/2+5/4=7/4
这时x=π/6