∵函数y=asin(wx+φ)+k(a>0w>0)
当x=5π/3时y取最大值7/3,当x=11π/3时,y取最小值-2/3
∴可知a=(7/3+2/3)/2=3/2 k=7/3-3/2=5/6
周期T=2*(11π/3-5π/3)=4π
故2π/w=4π,w=1/2
得到：y=3/2sin(x/2+φ)+5/6 ,将x=5π/3代入,
7/3=3/2sin(5π/6+φ)+5/6,得出：φ=-π/3
得到y=3/2sin(x/2-π/3)+5/6