Question

谁能把此题的详细答案写下来，最好能写在纸上

Answer 1

f(x)=sin(2x+θ)+√3cos(2x+θ)
=2[1/2sin(2x+θ)+√3/2cos(2x+θ)]
=2sin(2x+θ+π/3)
∵是奇函数
∴f(-x)=-f(x)
2sin(-2x+θ+π/3)=-2sin(2x+θ+π/3)
sin(-2x+θ+π/3)=sin(-2x-θ-π/3)
θ+π/3=-θ-π/3+2kπ
2θ=-2π/3+2kπ
θ=-π/3+kπ
当k=1时，θ=2π/3
选B。