Gaokao Math Practice Question
已知 $\alpha \in(0, \pi)$, 且 $3 \cos 2 \alpha-8 \cos \alpha=5$, 则 $\sin \alpha=(\qquad)$
- A.$\frac{\sqrt{5}}{3}$
- B.$\frac{2}{3}$
- C.$\frac{1}{3}$
- D.$\frac{\sqrt{5}}{9}$
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