f(x+2θ)=sin[2(x+θ)-π/3]=sin(2x+2θ-π/3)
为偶函数的话
2θ-π/3=kπ+π/2
θ=kπ/2+5π/3 集合{θ|θ=kπ/2+5π/3,k∈Z}θ∈【0,π/2】时,
θ=-3π/2+5π/3=π/6