5.已知 $\sin \theta+\sin \left(\theta+\frac{\pi}{3}\right)=1$ ,则 $\sin \left(\theta+\frac{\pi}{6}\right)=$
参考答案B
2020_新课标 III 卷 (2020·文)
5.已知 $\sin \theta+\sin \left(\theta+\frac{\pi}{3}\right)=1$ ,则 $\sin \left(\theta+\frac{\pi}{6}\right)=$