Câu hỏi:
- A \(\cos \alpha = \frac{{\sqrt 5 }}{3};\,\,\tan \alpha = - \frac{2}{3};\,\,\cot \alpha = - \frac{{\sqrt 5 }}{2}\)
- B \(\cos \alpha = \frac{{\sqrt 5 }}{3};\,\,\tan \alpha = \frac{{2\sqrt 5 }}{5};\,\,\cot \alpha = \frac{{\sqrt 5 }}{2}\)
- C \(\cos \alpha = \frac{{\sqrt 2 }}{3};\,\,\tan \alpha = \sqrt 2 ;\,\,\cot \alpha = \frac{1}{2}\)
- D \(\cos \alpha = \frac{1}{3};\,\,\tan \alpha = 2;\,\,\cot \alpha = \frac{1}{2}\)
Lời giải chi tiết:
