6.(2022秋•福田区校级月考)已知ΔABC\Delta ABCΔABC的内角AAA,BBB,CCC所对的边分别为aaa,bbb,ccc,A=π6A=\frac{\pi }{6}A=6π,a=1a=1a=1,b=3b=\sqrt{3}b=3,若函数f(x)=sin(2x+B)f(x)=\sin (2x+B)f(x)=sin(2x+B)在(0,π4)({0,\frac{\pi }{4}})(0,4π)上存在零点,则B=(B=(B=( )))